State Attorney General Bob Ferguson filed suit seeking to block US President Donald Trump's executive order temporarily banning foreign refugees, media reports said.

"No one is above the law, not even the president," Los Angeles Times quoted Ferguson as saying while announcing the federal lawsuit. "And in the courtroom, it is not the loudest voice that prevails. It's the Constitution."

Ferguson became the first state attorney general to announce a legal action against the Trump administration over one of its policies.

Trump signed an executive order on Friday that suspends all immigration for citizens of seven countries -- Iran, Iraq, Sudan, Yemen, Syria, Libya and Somalia -- for 90 days.

Ferguson was one of 16 state attorneys general who released a statement Sunday calling Trump's immigration action "un-American and unlawful."   

Ferguson said the lawsuit against Trump and high-ranking Trump administration officials would be filed later on Monday in federal court in Seattle, US.