The United States Department of Justice has filed a notice of appeal against a decision by a federal judge in Maryland to strike down parts of President Donald Trump's revised travel ban.
It came hours before the ban was to have taken effect.
White House Press Secretary Sean Spicer told a media briefing the government would "vigourously defend this executive order" and appeal against the "flawed rulings."
The appeal is set to be heard in the Fourth Circuit court in Richmond, Virginia.
Maryland Judge Theodore Chuang on Thursday issued an emergency halt to the portion of President Donald Trump's 6 March executive order, which temporarily banned the entry of travellers from six Muslim-majority countries.
The judge left in place a section of the order that barred the entry of refugees to the US for four months.
Another federal judge in Hawaii struck down both sections of the ban in a broader court ruling that prevented Mr Trump's order from moving forward.
In Washington state, where the ban is also being challenged, Judge James Robart put a stay on proceedings for as long as the Hawaii court's nationwide temporary restraining order remained in place.
The Ninth Circuit court last month upheld a decision by Judge Robart that halted an original, more sweeping travel ban signed by Mr Trump on 27 January in response to a lawsuit filed by Washington state.
Mr Trump issued the amended executive order with the intention of overcoming the legal concerns.
The president has said he would take his case for the ban - on the grounds of national security - to the Supreme Court.
- BBC / Reuters