Baghdad ? Iraqi officials stepped up pressure on the United States on Tuesday to agree to a specific timeline to withdraw American forces, a sign of the government’s growing confidence as violence falls.

The tough words come as the Bush administration is running out of time to reach a needed troop deal before the U.S. election in November and the president’s last months in office. Some type of agreement is required to keep American troops in Iraq after a U.N. mandate expires on Dec. 31.

The Iraqi timeline proposal made public Tuesday appears to set an outer limit, requiring U.S. forces to fully withdraw five years after the Iraqis take the lead on security nationwide – though that precondition could itself take years.

“Our stance in the negotiations under way with the American side will be strong,” said Iraq’s national security adviser, Mouwaffak al-Rubaie, a day after Prime Minister Nouri al-Maliki first publicly said he expects some type of timeline. “We will not accept any memorandum of understanding that doesn’t have specific dates to withdraw foreign forces from Iraq.”

President Bush has said he opposes a timeline.