A US judge in Seattle has issued a temporary nationwide block on President Donald Trump's ban on travellers from seven Muslim nations, media reports said.

US District Court Senior Judge James L. Robart on Friday granted the injunction at the request of Washington state Attorney General Bob Ferguson, whose office said that the order applies nationwide, media reported.

"The Constitution prevailed today. No one is above the law - not even the President," Ferguson said.

The lawsuit against Trump's ban was initially filed by Washington state, with Minnesota joining later.

Ferguson has described the ban as illegal and unconstitutional, because it discriminates against people on the ground of their religion.

The ruling is a major challenge to the Trump administration, and means that nationals from the seven countries are now able - in theory - to apply for US visas, the BBC said in its report.

The administration can appeal against the verdict.
 

Last week's move by Trump triggered mass protests and has resulted in confusion at US airports.

The State Department says 60,000 visas have since been revoked.

Trump's executive order brought in a suspension of the US Refugee Admissions Programme for 120 days.

There is also an indefinite ban on Syrian refugees. Anyone arriving from Iraq, Syria, Iran, Libya, Somalia, Sudan, and Yemen faces a 90-day visa suspension.