WASHINGTON — U.S. congressional Democrats introduced legislation on Thursday to block President Donald Trump's plan to remove 9,500 troops from close ally Germany by prohibiting funding for a withdrawal of U.S. forces from Europe without congressional approval.

Representative Eliot Engel, chairman of the House of Representatives Foreign Affairs Committee, and Senator Bob Menendez, ranking Democrat on the Senate Foreign Relations Committee, introduced the bill, reflecting concern in Congress from Democrats as well as Trump's fellow Republicans about the plan to cut troops.

Trump said on Monday he would reduce the number of U.S. troops in Germany to 25,000, faulting Berlin for failing to meet NATO's defense spending target and accusing it of taking advantage of the United States on trade.

The troop reduction would be a remarkable rebuke to one of the closest U.S. trading partners and could erode faith in a pillar of postwar European security: that U.S. forces would defend alliance members against Russian aggression.

Under the U.S. Constitution's separation of powers, the Senate and House of Representatives - not the White House - control government spending.

Lawmakers often use their power of the purse to influence policy decisions, such as keeping the prison camp at Guantanamo Bay open by barring spending federal money to close it.

The bill would prohibit the use of funds to withdraw or reduce the presence of U.S. armed forces in Europe unless the host government requests it, or the president declares the intent 180 days in advance, justifies the decision, Congress approves it and the secretaries of State and Defense testify about it.

"President Trump's disastrous decision to withdraw thousands of troops from and reduce the total force cap in Germany endangers our national security," Engel said in a statement.

"Our legislation will stop the Administration from carrying out this calamitous policy," he said.