US President Donald Trump says he is skeptical 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 agree to a new bill by February 15 to avoid another shutdown.
The US economy lost $3bn (£2.2bn) from the closure of federal agencies, according to the non-partisan Congressional Budget Office on Monday.
Its analysis said the economy overall shed about $11bn during the five-week period, but about $8bn would be recouped as employees receive back pay.
A committee of lawmakers from both parties is poised to negotiate, but M r Trump told the Journal the chances of a political breakthrough are "less than 50-50".