KABUL/GENEVA (CHINA DAILY/ASIA NEWS NETWORK, REUTERS) - Taleban co-founder Abdul Ghani Baradar said the group intends to establish ties with all countries around the world, denying reports that they do not want ties with the United States.

"The Islamic Emirate of Afghanistan wants diplomatic and trade ties with all countries, particularly with the United States of America," Mr Baradar wrote on social media platform Twitter on Saturday (Aug 21).

"We never talk about cut of trade ties with any countries. Rumour about this news has been propaganda. It is not true," he said.

Earlier in the day, reports said that Mr Baradar has arrived in the Afghan capital Kabul for talks with other leaders about the creation of a new government. He returned to Kandahar from Doha, capital of the Gulf state of Qatar last Tuesday.

A spokesman for the Islamist movement said the Taleban aims to unveil a new governing framework for Afghanistan in the next few weeks.

"Legal, religious and foreign policy experts in the Taleban aim to present the new governing framework in the next few weeks," the spokesman told Reuters on Saturday.

The Taleban follow an ultra-hardline version of Sunni Islam. They have sought to present a more moderate face since returning to power, saying they want peace and will respect the rights of women within the framework of Islamic law.

When in power from 1996 to 2001, also guided by Islamic law, the Taleban stopped women from working or going out without wearing an all-enveloping burqa and stopped girls from going to school.

Individual Afghans and international aid and advocacy groups have reported harsh retaliation against protests, and round-ups of those who had formerly held government positions, criticised the Taleban or worked with US-led forces.

"We have heard of some cases of atrocities and crimes against civilians," the Taleban official said. "If (members of the Taleban) are doing these law and order problems, they will be investigated," he said.

United Nations officials warned last Friday that the situation across Afghanistan remained extremely fluid, adding that bolstered support for the humanitarian response within the country Afghanistan was urgently needed.

Ms Shabia Mantoo, spokesman for the UN Refugee Agency, said at a press briefing in Geneva that while widespread fighting had decreased since the takeover of the country by the Taleban last Sunday, the full impact of the evolving situation was not yet clear.

The vast majority of Afghans were not able to leave the country through regular channels, Ms Mantoo said, adding that some 200 colleagues from the UN Refugee Agency, both national and international, remained in Afghanistan.

US President Joe Biden last Friday once again defended his administration's handling of withdrawal from Afghanistan, denying America's allies questioning the country's credibility over the ongoing chaotic evacuation.

"This is one of the largest, most difficult airlifts in history, and the only country in the world capable of projecting this much power on the far side of the world with this degree of precision is the United States of America," said Mr Biden, who has been widely criticised on the botched pullout, in a televised speech from the White House.

Mr Biden said he has "seen no question of our credibility from our allies around the world".

"And all our allies have agreed with that...every one of them knew and agreed with the decision I made to end - jointly end - our involvement in Afghanistan," said Mr Biden with Vice-President Kamala Harris, Secretary of State Antony Blinken, Secretary of Defence Lloyd Austin and National Security Adviser Jake Sullivan standing behind him.

Calling the past week heartbreaking, Mr Biden said the US has made significant progress and evacuated from Afghanistan more than 18,000 people since July and 13,000 since Aug 14.

He pledged to use the full force of the US military to complete the withdrawal and bring Americans and their Afghan allies who assisted the US in the 20-year conflict to safety.

This is Mr Biden's second press conference at the White House since the Taleban took control of the Afghan capital of Kabul last weekend.

The world was shocked to see scenes of chaotic evacuation at the Kabul airport.

In his speech last Monday, Mr Biden said Kabul's fall to the Taleban came much sooner than Washington had anticipated.

Meanwhile, British Prime Minister Boris Johnson said last Friday that Britain will work with the Taleban "if necessary", as the group has regained the control of Afghanistan.

"What I want to assure people is that our political and diplomatic efforts to find a solution for Afghanistan - working with the Taleban, of course, if necessary - will go on," Mr Johnson told reporters.

He said the situation at the Kabul airport, where thousands of Afghans gathered in hopes of boarding an evacuation flight, was getting slightly better and he saw stabilisation.

Britain has been able to evacuate about 2,000 people, including British nationals and Afghans who worked with Britain, since last Thursday, the prime minister said.

The US and Germany told their citizens in Afghanistan on Saturday to avoid travelling to Kabul airport, citing security risks as thousands of desperate people gathered trying to flee almost a week after Taleban Islamists took control.

The Taleban has urged those without travel documents to go home. At least 12 people have been killed in and around the single-runway airfield since last Sunday, when the Taleban seized control of Afghanistan, Nato and Taleban officials said.

"Because of potential security threats outside the gates at the Kabul airport, we are advising US citizens to avoid travelling to the airport and to avoid airport gates at this time unless you receive individual instructions from a US government representative to do so," a US Embassy advisory said.

The German Embassy warned its citizens in an e-mail that Taleban forces were conducting increasingly strict controls in its immediate vicinity.

A Taleban official, speaking to Reuters, said security risks could not be ruled out but that the group was "aiming to improve the situation and provide a smooth exit" for people trying to leave over the weekend.

President Joe Biden will provide an update on Sunday on the administration's response to the evacuation of American citizens and refugees from Afghanistan, the White House said.

The president is to speak at 4pm local time (4am Monday Singapore time), after meeting with his national security team to hear intelligence, security and diplomatic updates on the evolving situation in Afghanistan, the White House said.

The Biden administration has told US airlines they could be ordered to help ferry people who have been evacuated from Afghanistan, two officials said on Saturday.

Speaking a day after Mr Biden promised to evacuate "any American who wants to come home", Pentagon spokesman John Kirby said he did not have a "perfect figure" on how many US citizens remain in Kabul and Afghanistan more broadly, though officials have indicated it is thousands.

Mr Kirby declined to describe the specific "threat dynamics" in Kabul but called the security situation fluid and dynamic. "We're fighting against both time and space," Mr Kirby said.

Former president Donald Trump launched on Saturday a sustained attack on Mr Biden's handling of the retreat of US forces from Afghanistan, which he called "the greatest foreign policy humiliation" in US history.

Mr Trump, a Republican who has dangled the possibility of running again for president in 2024, has repeatedly blamed Mr Biden, a Democrat, for Afghanistan's fall to the Islamist militant Taleban, even though the US withdrawal that triggered the collapse was negotiated by his own administration.

"Biden's botched exit from Afghanistan is the most astonishing display of gross incompetence by a nation's leader, perhaps at any time," Mr Trump said at a boisterous rally packed with his supporters near Cullman, Alabama.

For his part, Mr Biden has criticised the Afghan military for refusing to fight, denounced the now-ousted Afghan government and declared he inherited a bad withdrawal agreement from Mr Trump.

At the rally, Mr Trump blamed the situation on Mr Biden not having followed the plan his administration came up with and bemoaned US personnel and equipment being left behind as troops withdrew.

"This is not a withdrawal. This was a total a surrender," Mr Trump said.

He said the Taleban, with whom he had negotiated, respected him. He suggested the quick takeover of Afghanistan would not have happened if he was still in office.

"We could have gotten out with honour," Mr Trump added. "We should have gotten out with honour. And instead we got out with the exact opposite of honour."

In Qatar, which is hosting thousands of evacuees until they can enter a third country, Afghans who fled described in interviews with Reuters their despair at leaving behind loved ones while facing their own uncertain future.

A law student spoke of looting by the Taleban as they took control of Kabul, with armed militants intimidating people going to the airport. He left behind his wife, whom he married in a video call before evacuating.

"Our minds are back home because our families remain," he said, speaking on condition of anonymity like the other evacuees due to concerns for relatives left behind.

"It's going to be a very, very different and challenging life ahead of us," said a lawyer who arrived in Doha with his wife, three children, parents and two sisters.

Qatar's air force has evacuated Afghan nationals, students, foreign diplomats and journalists from Afghanistan, the Gulf country's government media office said on Twitter, giving no further details.

Switzerland postponed a charter flight from Kabul because of the chaos at the airport.