AUSTRALIAN senators heard yesterday that Washington has yet to send security officers to vet refugees held on Pacific islands for resettlement.

US President Donald Trump has reluctantly agreed to honour a pledge by predecessor Barack Obama to accept up to 1,250 refugees refused entry to Australia.

But he said they would be subject to “extreme vetting” before being granted asylum in the US.

Australia pays Nauru and Papua New Guinea to hold more than 2,000 refugees, mostly from Iran, Afghanistan and Sri Lanka, in foul conditions condemned by human rights campaigners.

Immigration and Border Protection Department secretary Mike Pezzullo told a senate committee that US Department of Homeland Security officers were set to start vetting refugees on the islands as soon as they were authorised to do so by the White House.

Mr Pezzullo told the legal and constitutional affairs committee he was confident there would be “movement within the next few, several months.”

“The present administration’s made it clear they are currently looking at their vetting thresholds,” he said.

Committee member Senator Nick McKim, who described Mr Trump as “insane,” questioned how Mr Pezzulo could have confidence in that time frame, given that the White House was “in absolute disarray.”

Mr Pezzullo replied that he was relying on advice from US Homeland Security and State Department officials.

State Department officials have already conducted preliminary interviews on the islands to ensure that candidates for resettlement were genuine refugees, he said.

Mr Trump has described the deal with Australia as “dumb” and raised doubts about whether it will proceed.