U.S. President George W. Bush on Friday signed a war-funding bill that erased a timetable to withdraw troops from Iraq from its previous version.

The move followed a bitter struggle with Democrats who sought unsuccessfully to tie the funding to timeline for U.S. troop withdrawals.

Bush had rejected a previous version of the bill because it contained a withdrawal timetable.

Faced with continued White House opposition after the veto, the Democratic leadership agreed to drop the withdrawal language so the bill could be signed by Bush before the end of the month.

Both the House of the Representatives and the Senate passed the new bill Thursday.

Signing the bill in Camp David, Maryland, Bush said Friday that the measure provides troops "with the funding and flexibility they need to protect our country."

"Rather than mandate arbitrary timetables for troop withdrawals or micromanage our military commanders, this legislation enables our servicemen and women to follow the judgment of commanders on the ground," he said.

Instead of setting any timetable, the bill contains a set of political benchmarks that the Iraqi government should meet to keep U.S. reconstruction aid flowing.

It also requires Bush to submit reports in July and September indicating progress in meeting those goals.

Nevertheless, the bill for the first time explicitly states that U.S. forces would leave Iraq if asked by the Iraqi government.

Democrats have vowed to continue their efforts to end the war even they were forced to drop timetable from the funding bill.

They are planning to write anti-war language into defense appropriations and defense authorization bills over the summer.

Meanwhile, moderate Republicans are growingly frustrated about Bush's unpopular war policy, worrying it could damp their chances in next year's elections.

It is unclear how long the president can count on the firm support from his fellow Republicans on Iraq policy.

Sen. John Warner, a Republican heavyweight, said if conditions in Iraq do not improve by mid-July, Bush should reconsider his strategy.