President Donald Trump has indicated he is prepared to sign the government funding bill and issue a national emergency decree on the border, a leading Republican has said.
Senate Majority Leader Mitch McConnell said the US Senate will soon vote on the bill that is needed to avoid a partial federal shutdown on Friday.
The comprise measure keeps departments running through the fiscal year but without the $5.7 billion Mr Trump wanted for the border wall with Mexico.
The House is also expected to vote on the bill later.
Mr Trump's assent would end a raucous legislative saga that commenced before Christmas and saw Mr Trump force a record 35-day partial US federal shutdown.
Mr McConnell also said he would support Mr Trump's emergency declaration, a change from the Republican, who like Democrats and many Republicans has until now opposed such a declaration.
The emergency declaration will inject the likelihood of fresh conflict between Congress and Mr Trump over his efforts to build barriers along the boundary with Mexico.
Opponents have said there is no crisis at the border and Mr Trump is merely sidestepping Congress.
The Republican-controlled Senate began voting on the agreement on Wednesday, and passage by that chamber and the Democratic-led controlled seemed certain.
Mr Trump had signalled he would sign the bill but it was unclear until Mr McConnell's announcement if he would do so, prompting some politicians to voice concern.
"Let's all pray that the president will have wisdom to sign the bill so the government doesn't shut down," said Senator Charles Grassley, chiming in after a guest chaplain opened Thursday's session.
Mr Trump's assent would end a raucous legislative saga that commenced before Christmas and was ending, almost fittingly, on Valentine's Day.
The low point was the historically long 35-day partial federal shutdown, which Mr Trump sparked and was in full force when Democrats took control of the House, compelling him to share power for the first time.
Mr Trump yielded on the shutdown on January 25 after public opinion turned against him and congressional Republicans.
It was a political fiasco for Mr Trump and an early triumph for House Speaker Nancy Pelosi.
Mr Trump made building a wall on the southern border his signature policy in his 2016 successful election campaign against Hillary Clinton.
The recent deadlock comes as Democrats hoping to challenge for the White House in 2020 have started to declare their intention to seek the party's nomination.