WASHINGTON - The United States will notify a first batch of 54 refugees of their acceptance to be resettled under a deal with Australia within days, a US official said Friday.

The refugees, held on Nauru and Papua New Guinea's Manus Island in the western Pacific, some of them for years, could arrive in the United States in weeks, according to the official.

The temporary US ban on refugee arrivals and the annual refugee cap will not be applied to the group, part of some 1,250 people that former US president Barack Obama agreed to accept in a deal with Canberra in November 2016.

In return Australia agreed to take an unspecified number of asylum-seekers from Central America that entered the United States illegally.

"Our commitment to the US-Australian alliance is important to us, and we know this is important for Australia," said the official, who asked to not be identified.

As a deterrent, Australia sends illegal arrivals to isolated detention camps with the aim of resettling them to third countries eventually.

More than 1,000 people, many of them from Iran, Pakistan, and Afghanistan, live in the camps on the two remote islands. Australia has labelled most of them "economic refugees".

The nationalities of those in the group of 54 have not been made public, but the US official said they have been cleared in security checks.

"All refugees approved for travel to the United States from Nauru and Papua New Guinea have passed the same stringent vetting processes that apply to all refugees considered for admission to the United States," the official said.

In January, just after Donald Trump became president, there were some worries that Washington would not honor Obama's agreement.

Trump became furious when Australian Prime Minister Malcom Turnbull raised the deal in a phone call. He told Turnbull the United States "has become like a dumping ground" and that Obama's agreement was a "disgusting deal," according to a transcript of the call.

"I hate taking these people. I guarantee you they are bad," Trump said at the time.