The border bill would provide $US1.37bn in new money to help build 88.5 km of new physical barriers on the border.
Levinson said to expect a legal battle once Trump declares a national emergency. The White House had attempted earlier this week to bolster support among Trump's media allies.
On Twitter, Trump said Thursday afternoon that he was "reviewing the funding bill with my team", but gave no indication of which way he was leaning on methods to fund the wall.
Should Trump change his mind, both chambers' margins were above the two-thirds majorities needed to override presidential vetoes. The declaration would allow Trump to deliver "on his promise to build the wall, protect the border, and secure our great country", Sanders said.
A state of emergency is declared in times of crisis.
McConnell told the Senate, "I've just had an opportunity to speak with President Trump, and he has indicated he's prepared to sign the bill". Mr. McConnell, who had previously warned him against such an action, will show he has perfected a trick: roll over and play dead.
Pelosi said she "may" mount a legal challenge against the declaration but did not not want to commit to anything until seeing Trump's explanation for his action.
Freedom Caucus chairman Mark Meadows of North Carolina said there would be no "political liability" from conservatives if he signs the measure and "also takes executive action".
GOP critics included ME senator Susan Collins, who said emergency declarations are for "major natural disasters or catastrophic events" and said its use would be of "dubious constitutionality".
During a press conference about the bill, Pelosi said that the situation at the border is a humanitarian issue, not a national emergency.
Velázquez also noted that there are discussions about moving other bills such as one she introduced to prevent money Congress appropriated for disaster relief from being used for the wall. But she added, "First of all, it's not an emergency, what's happening at the border". But according to the law, the money has to be used in support of USA armed forces, they say.
The Defense Department has declined to provide any details on the amount of money available. "Barriers" and "fencing" are the nouns of choice, a victory for Democrats eager to deny Mr Trump even a rhetorical victory. They objected to giving more funding for the "abusive" agencies on the front line of immigration enforcement: Customs and Border Protection and Immigration and Customs Enforcement. Ben McAdams, Utah's lone Democrat in Congress, voted for it.
The aide said it would be impossible for leaders to decide a path forward until they see what Trump does.
The legislation would also fund the Justice Department, Commerce Department, State Department, Department of Agriculture, Internal Revenue Service and others, covering roughly 800,000 federal workers. The impasse led to the previous 35-day-long partial government shutdown.
Trump wants to keep a campaign promise to build a wall on the U.S. border with Mexico.
House Democrats overwhelmingly backed the legislation, with only 19 - most of whom were Hispanic - opposed.
Trump's descriptions of the wall have fluctuated, at times saying it would cover 1,000 miles of the 2,000-mile boundary.