US President Donald Trump says he is sceptical a deal can be reached on border security before government funding expires again next month.
He spoke to the Wall Street Journal as 800,000 federal employees returned to work after the longest ever closure of federal agencies, lasting 35 days.
The Republican president said he doubts he would lower the sum he is prepared to accept for a US-Mexico border wall.
Congress must negotiate a new bill by 15 February to avoid another shutdown.
A committee of lawmakers from both parties is poised to negotiate, but Mr Trump said the chances of a political breakthrough are “less than 50-50”, the Journal reported.
Asked if he would accept less than the $5.7bn (£4.3bn) he wants to build a border barrier, he said: “I doubt it.”
“I have to do it right,” he added, noting that he has not ruled out a second shutdown in as many months to accomplish his signature campaign pledge.
The president also sounded unwilling to make any significant concession to strike a grand bargain with Democrats.
Mr Trump said he doubted he would back citizenship for immigrants who entered the US without documentation as children.
On Friday, the president bowed to mounting pressure to end the crippling shutdown of about a quarter of the US government.
But while Congress quickly passed a bill to fund federal agencies, Mr Trump again came away without a dollar of taxpayers’ money for his long-promised border wall.
His perceived retreat provoked a welter of conservative criticism, prompting him unusually to lash out at his favourite cable show, Fox News.
Mr Trump tweeted on Sunday: “Never thought I’d say this but I think @johnrobertsFox and @GillianHTurner @FoxNews have even less understanding of the Wall negotiations than the folks at FAKE NEWS CNN & NBC!”
In a first version of that tweet, the president misspelled Fox correspondent Gillian Turner’s name as Jillian – tagging an unsuspecting California teenager instead.
He also took a dig at right-wing commentator Ann Coulter – who last week labelled him a wimp – telling the Wall Street Journal: “I hear she’s become very hostile.
“Maybe I didn’t return her phone call or something.”
Meanwhile, as the president rails against illegal immigrants, reports have emerged in recent weeks that his own golf resorts have been hiring undocumented workers for years.
On Saturday, the Associated Press reported that a dozen undocumented immigrants employed at Mr Trump’s New York club were abruptly fired.
A lawyer for the staff said managers had been aware of their legal status for years, but had adopted a “don’t ask, don’t tell” attitude.
Many of those dismissed had worked at the club for over 12 years, and one employee had the keys to the bedroom of the president’s 35-year-old son, Eric Trump, according to reports.
Last month, a housekeeper at a Trump club in New Jersey told the New York Times managers had knowingly hired undocumented immigrants.