SYDNEY (AFP) - The first of 12,000 refugees fleeing the conflict in Syria to be resettled by Australia will arrive within 24 hours, the government said on Monday (Nov 16), as concerns about security checks mounted after bloody attacks in Paris.

Meanwhile in the United States, two states say they will block or suspend a programme to resettle Syrian refugees within their borders.

Australia, which has joined US-led air strikes on the Islamic State in Iraq and Syria (ISIS), said in September it would boost its humanitarian refugee intake by 12,000 in the face of the unrest in the Middle East.

The first arrivals, a family of five from Homs, were to arrive in the western city of Perth before Tuesday evening, said Australia's Social Services Minister Christian Porter.

"The family has been through a great deal," Porter told reporters, adding that they had spent a long time in refugee camps.

The resettlement comes just days after a deadly coordinated attack in Paris claimed by ISIS that killed at least 129 people.

Before the announcement in September of the increased refugee quotas, Australia had already agreed to resettle more than 13,000 from around the world in the 2015-16 fiscal year.

The additional 12,000 spots are for those fleeing conflict in Syria and Iraq.

Questions about Australia's refugee intake have intensified since the attacks, after the discovery of a Syrian passport near the body of one assailant raised fears that some of them may have entered Europe as part of the huge influx of people fleeing Syria's civil war.

French Prime Minister Manuel Valls said Monday the gruesome attacks had been planned in Syria and warned of further unrest being planned in France and Europe.

Porter stressed that Australia's refugee selection process had been rigorous and he expected a positive response to the arrival of the family - a couple and three children.

"Their processing has been orderly - some would say very, very slow - but very, very thorough," he said.

"It has all of the level of stringency that occurs for all humanitarian and refugee arrivals." But a New South Wales state politician had earlier called on Australia in a post on Facebook to close its borders to refugees from the Middle East.

"We need the borders closed until such time as we can be assured that we are not getting terrorists into Australia under the guise of refugees," MP Andrew Fraser said in comments cited by the Australian Broadcasting Corporation.

But the government has rejected the idea and Attorney-General George Brandis has said the "worst thing we could do is to alienate the Muslim community".

And Porter said he expected no difficulty for the Syrian family, who would be met by officials at the airport.

"There has been nothing other than immense generosity... from the Australian people," he said.

In contrast, two states in the US say they will block or suspend a programme to resettle Syrian refugees within their borders, citing security concerns after the deadly assaults in Paris.

"After full consideration of this weekend's attacks of terror on innocent citizens in Paris, I will oppose any attempt to relocate Syrian refugees to Alabama," said Robert Bentley, governor of the southern US state.

"As your governor, I will not stand complicit to a policy that places the citizens of Alabama in harm's way," Bentley said in a statement on Sunday.

"The acts of terror committed over the weekend are a tragic reminder to the world that evil exists and takes the form of terrorists who seek to destroy the basic freedoms we will always fight to preserve," the governor added. "I will not place Alabamians at even the slightest possible risk of an attack on our people."

The governor of the midwestern US state of Michigan said on Sunday that he had decided to suspend arrivals of Syrian refugees under a programme announced President Barack Obama.

"Given the terrible situation in Paris, I've directed that we put on hold our efforts to accept new refugees until the US Department of Homeland Security completes a full review of security clearances and procedures," Governor Rick Snyder said in a statement quoted in some US media on Sunday.

"There will be difficult days ahead for the people of France and they remain in our thoughts and prayers," said Snyder, whose state is home to one of America's largest concentration of inhabitants from the Middle East.

"It's also important to remember that these attacks are the efforts of extremists and do not reflect the peaceful ways of people of Middle Eastern descent here and around the world," he added in his statement.

The leading newspaper in his state, the Detroit Free Press, reported that between 1,800 and 2,000 refugees have resettled in Michigan over the past year, about 200 of whom were from Syria.

Another US governor, Bobby Jindal of Louisiana, who also is running for the Republican party's 2016 presidential nomination, on Saturday sent a letter to President Barack Obama expressing "grave concern" about allowing Syrian migrants into the country, and saying it would be "prudent to pause the process."

"Authorities need to investigate what happened in Europe before this problem comes to the United States," Jindal wrote to Obama.

Jindal said Syrian refugees began arriving in New Orleans earlier this month, and said it is "irresponsible and severely disconcerting to place individuals, who may have ties to ISIS, in a state without the state's knowledge or involvement."

Friday's attacks in Paris that left at least 129 dead and hundreds injured have raised fears of a similar assault by Islamist extremists on US soil.

Obama announced in September that the United States would take in 10,000 Syrian refugees by September 2016.

Various Republican presidential hopefuls also insisted on Sunday that in the wake of the Paris attacks America must not take in Syrian refugees because they might include Islamic State militants.

But a White House aide said the plan to bring Syrian refugees into the country carries very little risk, because the vetting process is "robust" and the overall number of refugees relatively small.

"We cannot close our doors to these people," Ben Rhodes, Obama's deputy national security adviser told the Fox News Sunday programme.