The replacement of Secretary of State Rex Tillerson with Central Intelligence Agency director Mike Pompeo signals a State Department more in line with President Donald Trump's hardline approach to key challenges abroad, including North Korea, Iran and the trade deficit with China.

"I am really at a point where we are getting very close to having the Cabinet and other things that I want," Mr Trump said on Tuesday.

The President is consolidating a team of hawks that shares his thinking, analysts say. There is speculation that National Security Adviser H.R. McMaster may be the next high-profile figure to resign or be replaced. Although General McMaster is seen as hawkish, several names being considered are arguably more so, including Mr John Bolton, a former United States ambassador to the United Nations.

Mr Pompeo is a former Tea Party congressman who served three terms in the state of Kansas. As CIA chief, he has been meeting the President almost daily. Mr Trump told reporters on Tuesday: "We have a very similar thought process. We are always on the same wavelength. The relationship has been very good. That is what I need as secretary of state."

Mr Trump said while he got along with Mr Tillerson, they disagreed on issues such as the Iran deal, which he thought was "terrible", but Mr Tillerson thought was okay.

The 2015 Iran deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), was agreed on by the US, Britain, Russia, China, France, Germany, the European Union and Iran. It led to Teheran suspending its nuclear weapons programme, which inspectors have said it has been in compliance with.

But Mr Trump has insisted that Iran's missile programme and the state's links with militant groups abroad violate the deal in spirit.

"Pompeo is a vocal critic of the JCPOA and his confirmation likely will spell the end of the agreement," the consultancy Soufan Group said, adding that such a move may torpedo upcoming talks with North Korea over its own nuclear programme. "It is unlikely Pyongyang would sign a nuclear agreement if the US walks away from a signed agreement with Iran."

BowerGroup Asia CEO Ernie Bower said there is a "sense of angst, worry and deep concern over the direction of US foreign policy and governance in general".

"This is true across Asia," he added.

Ms Shannon Hayden, associate director of the South-east Asia Programme at the Centre for Strategic and International Studies, said: "Tillerson's credibility with foreign counterparts was very weak in that they knew he did not speak for Trump."

She said Mr Pompeo is more aligned with Mr Trump's thinking on a range of issues.

"In that regard, he should be more effective. But he is also seen as broadly hawkish, which is worrisome in the context of major international challenges - North Korea and Iran, chiefly," she added.

Dr Jessica Chen Weiss, professor of government at Cornell University, said a potential silver lining is that the State Department will fare better under someone who has Mr Trump's ear, but added: "China and Asia can probably expect more of Trump's wild swings between rhetorical confrontation and cooperation."

While Mr Pompeo has shown a high regard for Chinese President Xi Jinping as a strongman, he has also pointed to China's capacity to "present the greatest rivalry to America of any of those over the medium and long term", she said.

Ms Yun Sun, co-director of the East Asia Programme at the Stimson Centre, told The Straits Times: "The view of Pompeo in China is not positive. When they look at what he has said about China, it has not been positive."

CIA director Mike Pompeo, the hawkish pick for the post of top US diplomat, could further harden President Donald Trump's foreign policy positions, making it more difficult for moderate views to get an airing in the Oval Office. Here are his views on a range of major global issues:

ON NORTH KOREA

This administration has in its eyes wide open. And the whole time this conversation takes place, the pressure will continue to mount on North Korea.

MR MIKE POMPEO, in an interview with CBS news on Sunday, on the planned summit between President Donald Trump and North Korean leader Kim Jong Un.

ON CHINA AS A SECURITY THREAT

Think about the scale of the two economies. The Chinese have a much bigger footprint upon which to execute that mission than the Russians do.

MR POMPEO, in a BBC interview in January, where he said that Beijing was better positioned to carry out covert activities against the US than Moscow.

ON HOW THE U.S. WOULD DEAL WITH CHINA

If you look at (President Xi Jinping's) national security strategy, it was very clear that in what the Chinese are doing, whether that would be on trade or the theft of intellectual property or their continued advancement in East and South China seas, this administration is prepared and engaged in pushing back against the Chinese threats so that we can have a good relationship with China in a way that the world desperately needs.

MR POMPEO, speaking to Fox News on Sunday.

ON THE IRAN NUCLEAR DEAL

I look forward to rolling back this disastrous deal with the world's largest state sponsor of terrorism.

MR POMPEO, on his personal Twitter account, which was deactivated once he became head of the CIA.

ON ALLEGED RUSSIAN INTERFERENCE

There has not been a single indication that any vote was changed, that ballots were tampered with or that there was any outcome determined by the intelligence community. The intelligence community has simply said that is not our role to make that determination.

MR POMPEO, speaking to Fox News on Sunday. He has said that the Russians did attempt to interfere in the United States election in 2016, but declined to comment if it had any impact on the outcome.

ON THE LONG-RUNNING SYRIAN WAR

The previous president should have acted in Syria, and the previous president instead chose to invite the Russians in and that was a major turning point. Today, we find ourselves in the position where we are working to develop partners and those who are willing to work alongside us to get the best outcome for America.

MR POMPEO, referring to former president Barack Obama, on NBC news in July last year.

• SOURCES: BLOOMBERG, REUTERS, BBC