WASHINGTON — Top House Democrats retreated yesterday from an attempt to limit President Bush’s authority for taking military action against Iran as the leadership concentrated on a looming confrontation with the White House over the Iraq war.

Officials said Rep. Nancy Pelosi and other members of the leadership had decided to strip from a major military spending bill a requirement for Mr. Bush to gain approval from Congress before moving against Iran.

Conservative Democrats as well as lawmakers concerned about the possible impact on Israel had argued for the change in strategy.

The developments occurred as Democrats pointed toward an initial test vote in the House Appropriations Committee on Thursday on the overall bill, which would require the withdrawal of American combat troops from Iraq by September 1, 2008, if not earlier. The measure provides nearly $100 billion to pay for fighting in two wars and includes more money than the president requested for operations in Afghanistan and what Democrats called training and equipment shortages.

The White House has issued a veto threat against the bill, and Vice President Cheney attacked its supporters, declaring that they “are telling the enemy simply to watch the clock and wait us out.”

Meanwhile, Iran issued a bank note emblazoned with a nuclear symbol yesterday, in a move seen as an assertion of the national will in the face of international sanctions over its insistence on enriching uranium.

The new note for 50,000 rials (about $5.40) also reflected rising inflation, a fact that has brought criticism of President Ahmadinejad’s policies. It is worth more than twice the previously highest denomination note.