UPDATE | Trump scrambles to keep campaign promise as shutdown looms

WASHINGTON (AP) — Under intense political pressure from his conservative base, President Donald Trump is trying to find a way to fulfill a central promise from his 2016 campaign, constructing a border wall with Mexico, as the specter of a holiday shutdown looms.

In a dramatic showdown, Trump told House Republican leaders today he will not back a Senate-passed spending measure to avert a partial federal shutdown because it lacks the money he is demanding for the wall. Without a deal, the government will partially shut down Friday at midnight.

Trump's declaration came amid growing outrage from conservative allies who are urging the president to veto any plan that doesn't meet his terms. They said Trump would have even less leverage when Democrats take control of the House on Jan. 3 and they worry that Trump's failure to make good on his signature campaign pledge could hamper his re-election campaign in 2020.

By tweet and official statement, the White House made its position clear.

Trump "does not want to go further without border security," including the wall, press secretary Sarah Huckabee Sanders said.

Later, House Speaker Paul Ryan, R-Wis., told reporters after a hastily arranged White House meeting Trump had said he would not "sign the bill that came up from the Senate last evening because of his legitimate concerns for border security."

Trump complained on Twitter he "was promised" by congressional leaders that the wall and border security would be "done by end of year (NOW)."

"It didn't happen! We foolishly fight for Border Security for other countries - but not for our beloved U.S.A. Not good!" he wrote.

He also lashed out at Democrats: "I will not sign any of their legislation, including infrastructure, unless it has perfect Border Security." He also argued that border security is "tight" due to military and law enforcement efforts.

Throughout Trump's 2016 campaign, "Build the wall!" was a rallying cry. Trump supporters sought to remind him of that as they pushed him to veto the short-term plan.

On "Fox and Friends" today, Rep. Mark Meadows, R-N.C., said: "If we're not going to fight now, when are we going to fight?" The night before, he said that failing to veto the measure would cause "major damage" to Trump's re-election prospects. "The base will just go crazy," he said.

1:32 p.m.

WASHINGTON — President Trump announced today he won't sign a bill preventing a government shutdown without funding for his border wall and updated border security.

This is a breaking news story. Check Vindy.com for updates.