Senator Lindsey Graham called on President Trump to "use emergency powers to fund the construction of a border wall/barrier" in a statement on Thursday.

"Speaker (Nancy) Pelosi's refusal to negotiate on funding for a border wall/barrier -- even if the government were to be reopened -- virtually ends the congressional path to funding for a border wall/barrier," Graham said in a statement. "It is time for President Trump to use emergency powers to fund the construction of a border wall/barrier."

The statement from the key Trump ally came shortly after Graham said efforts to forge a deal with congressional Democrats had fallen flat.

Trump has repeatedly floated funding his wall by declaring a national emergency. On Thursday, he reaffirmed his position a day after walking out on Democrats at a White House meeting to resolve their impasse over his wall.

"If this doesn't work out, probably I will do it, I would almost say definitely," Trump said. "This is a national emergency."