Nearly 900 refugees will be allowed to enter the US despite Donald Trump's executive order

Senior US official says waivers allowed under order where refugees ready for travel and stopping them would cause 'undue hardship'

Communication among government agencies about order has 'not been the best' acting commissioner of US Customs and Border Protection agency says (AP)

Nearly 900 refugees will be allowed into the United States this week despite Donald Trump’s executive order suspending the nation's refugees program.

Kevin McAleenan, acting commissioner of the US Customs and Border Protection agency, said 872 refugees would be granted waivers.

Mr McAleenan told a news conference the move was allowed under the order in instances where refugees were ready for travel and stopping them would cause “undue hardship”.

He said the refugees will be arriving this week and will proceed for waivers through the end of the week.

Since the order, 721 travellers trying to enter from the seven countries were denied entry, Mr McAleenan said.

The Trump administration executive order suspends the US refugee program for four months, indefinitely bans all those from war-ravaged Syria, and temporarily freezes immigration from Iraq, Syria, Iran, Sudan, Libya, Somalia and Yemen.

It also led to a public showdown between Mr Trump and the acting US attorney general, who was fired late on Monday after she challenged the constitutionality of the order.

Mr McAleenan said it was fair to say that communication among government agencies on the order had “not been the best”.

At the briefing, Homeland Security Secretary John Kelly denied reports he had been out of the loop in the White House planning for the immigration restrictions.

MR Kelly told reporters he looked at two drafts of the order before it was signed on Friday, and added that high-level government lawyers and agency officials were involved in drafting it.

He also said he knew it was coming because Mr Trump had discussed it several times during his presidential campaign.

It comes as San Francisco became the first state to sue Mr Trump over a separate executive order withholding money from cities that have adopted sanctuary policies toward undocumented immigrants.

Mr Trump signed the directive on sanctuary cities on 25 January, along with an executive order to build a wall along the US-Mexican border, as he charged ahead with sweeping and divisive plans to transform how the US deals with immigration and national security.