WASHINGTON (Reuters) - U.S. President Donald Trump pressed fellow Republicans in Congress on Thursday to “get tough” and push to fund his proposed border wall in the current spending bill, raising the specter of a government shutdown when funding lapses later this month.

FILE PHOTO: U.S. President Donald Trump listens to a question from a reporter before departing the White House in Washington, U.S., September 19, 2018. REUTERS/Brian Snyder

In a post on Twitter, Trump called the bill “ridiculous” for not including funds for a planned wall along the U.S. border with Mexico, and blamed Democrats for blocking it in the plan passed by the Republican-controlled Senate on Tuesday.

The Senate-approved massive spending package included a provision to fund the federal government through Dec. 7 in an effort to avoid a government shutdown when funding ends Sept. 30.

The move gives lawmakers more time to finalize plans for next year’s spending, and avoids potentially angering voters who could be left without services from federal agencies weeks before the Nov. 6 congressional elections.

Republicans, who are seeking to keep control of both chambers in the November election, narrowly control the Senate with 51 seats against 49 for Democrats, and need Democrats’ support to pass any spending legislation.

The spending legislation must pass the Republican-controlled U.S. House of Representatives before it can be signed into law by Trump.

Trump has previously threatened to let the government shut down on Oct. 1 if he does not get money for the border wall.

“I want to know, where is the money for Border Security and the WALL in this ridiculous Spending Bill, and where will it come from after the Midterms? Dems are obstructing Law Enforcement and Border Security. REPUBLICANS MUST FINALLY GET TOUGH!” Trump said on Twitter.

Trump is seeking to make good on a key campaign promise to build the wall, but had long pledged that Mexico -- not U.S. taxpayers -- would fund it, something Mexico has refused to do. He has now, instead, turned to Congress for support.

Lawmakers have so far failed to reach any larger deal over immigration, a major campaign issue, but have allotted nearly $1.6 billion this year for border security.

The current measure, which the Senate approved in a 93-7 vote, includes $855 billion to fund the U.S. health, education and defense departments, and a continuing resolution to fund other parts of the government at current levels until the rest of the spending plan is approved.

The White House has not yet said whether Trump would sign the measure, if it is also approved by the House, which will have to take up the legislation when it returns to session Sept. 25.

Representatives for the White House did not immediately reply to a request for more details about Trump’s tweet.