SYDNEY (Reuters) - U.S. Homeland Security officials have begun “extreme vetting” interviews at Australia’s offshore detention centers, two sources at the camps told Reuters on Tuesday, as Washington honors a refugee swap that U.S. President Donald Trump had called “a dumb deal”.

An undated handout image from Amnesty International claiming to show the view of the family living quarters at the country's Australian-run detention centre on the Pacific island nation of Nauru. Amnesty International/Handout via REUTERS

The Trump administration said last month the agreement to offer refuge to up to 1,250 asylum seekers in the centers would progress on condition that refugees satisfied strict checks.

In exchange, Australia has pledged to take Central American refugees from a center in Costa Rica, where the United States has expanded intake in recent years, under the deal struck with former President Barack Obama.

The first security interviews finished last week at Papua New Guinea’s Manus Island detention center, two refugees who went through the process told Reuters.

The refugees told Reuters that interviews began with an oath to God to tell the truth and then proceeded for as long as six hours, with in-depth questions on associates, family, friends and any interactions with the Islamic State militant group.

“They asked about why I fled my home, why I sought asylum in Australia,” said one refugee who declined to be named, fearing it could jeopardize his application for U.S. resettlement.

The security interviews are the last stage of U.S. consideration of applicants.

Manus Island is one of two Australian-operated detention centers, which hold nearly 1,300 people who were intercepted trying to reach Australia by boat.

Human rights groups have condemned the intercept policy and the harsh conditions of the camps. Australia says offshore processing is needed as a deterrent after thousands of people drowned at sea before the policy was introduced in 2013.

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A decision on the fate of the first 70 people interviewed is expected to be reached within the next month, a different source who works with refugees said.

A spokesman for Australia’s immigration minister refused to comment on the resettlement process.

A U.S. State Department spokeswoman said that refugees from the Australian-run facilities will be subject to the same stringent vetting applied to all refugees who are being considered for entry to the United States.

“The United States remains deeply committed to safeguarding the American public, just as we are committed to providing refuge to some of the world’s most vulnerable people. These goals are not mutually exclusive,” she said.

The White House did not immediately respond to questions.

U.S. President Donald Trump’s plans for extreme vetting have extended to those traveling to the United States from Muslim countries.

Australia’s relationship with the new administration in Washington got off to a rocky start when Trump lambasted Australian Prime Minister Malcolm Turnbull over the resettlement arrangement, which Trump labeled a “dumb deal”.

Details of an acrimonious phone call between the pair soon after Trump took office made headlines around the world. Australia is one of Washington’s staunchest allies and has sent troops to fight alongside the U.S. military in conflicts in Iraq and Afghanistan.

The relocation of asylum seekers to the United States is designed to help Papua New Guinea and Australia proceed with the planned closure of the Manus detention center on Oct. 31.

But the fate of approximately 200 men deemed non-refugees is uncertain.

Those not offered resettlement in the United States will be offered the chance to settle in Papua New Guinea or return home.

Australia has already offered detainees up to $25,000 to voluntarily return home; an offer very few have taken up.