A United States (US) federal judge on Saturday lifted Trump administration restrictions that barred some refugees from the country, the latest in a series of immigration-related legal setbacks for the president.

The US said in October that it would resume accepting refugees after a 120-day ban ordered by President Donald Trump expired, but some ─ including those from 11 "high-risk" countries, most of which are Muslim majority ─ were still barred from entering.

In his ruling on Saturday, Judge James Robart ordered American authorities to resume processing and admitting so-called "follow-to-join" refugees, which would once again allow the spouse and unmarried children of a refugee already in the country to be admitted.

And he also ordered that "follow-to-join" refugees and "other refugees with a bona fide relationship to a person or entity within the United States" from the 11 "high-risk" countries be processed and admitted as well.

The ruling is in response to motions for preliminary injunctions filed in two separate cases.

"Plaintiffs in both cases are refugees, who find themselves in dire circumstances, their family members who yearn to be reunited with them, and humanitarian organisations whose fundamental mission is to help these vulnerable refugees resettle in the United States," Robart wrote in his ruling.

"Plaintiffs in both cases present compelling circumstances of irreparable harm inflicted by the federal agencies' action at issue here."

Trump's attempts at banning travellers from several mainly Muslim nations have been met with successive legal challenges this year.

Critics say the president's measures target Muslims, while the Trump administration has sought to cast the restrictions as being aimed at shoring up security.