A White House official launched a blistering attack on the court that blocked President Donald Trump's executive order on immigration on Sunday, calling its ruling a "judicial usurpation of power".
The Trump administration has faced multiple legal setbacks to its travel ban issued on January 27, and the Republican president has said he may issue a new executive order rather than go through lengthy court challenges.
"The President's powers here are beyond question," White House adviser Stephen Miller said on the Fox News Sunday program.
Mr Miller referred to immigration law that the executive order is based on that gives the US President broad powers to restrict who enters the country on national security grounds.
However, the same law forbids discrimination on race, sex, nationality or place of birth or residence. The case also could involve First Amendment protections involving religion.
The executive order Mr Trump issued banned entry into the United States to refugees and citizens of seven Muslim-majority countries, triggering nationwide protests and legal challenges.
A week later, a federal judge in Seattle issued a temporary restraining order that put the president's travel ban on hold, eliciting a barrage of angry Twitter messages from Mr Trump.
The judge's suspension was upheld by a three-judge panel of the 9th US Circuit Court of Appeals in San Francisco on Thursday.
Mr Miller, appearing on several television news shows, criticised the court and its ruling.
"The 9th Circuit has a long history of being overturned and the 9th Circuit has a long history of overreaching," he said.
"This is a judicial usurpation of power."
If the Seattle lawsuit goes to trial, Washington State Attorney General Bob Ferguson said on Sunday he will depose Trump administration officials to uncover "what truly motivated" the President's executive order.