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 the country’s prime minister 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,” al-Rubaie told reporters.

President Bush has said he opposes a timeline. The White House said Monday it did not believe Prime Minister Nouri al-Maliki was proposing a rigid timeline for U.S. troop withdrawals.

In Washington, the State Department declined to comment specifically on al-Rubaie’s remarks, saying it would not negotiate the agreement in public. But it reiterated that the United States fully intends to withdraw troops from Iraq when conditions are appropriate to do so.

“We want to withdraw. We will withdraw. However, that decision will be conditions-based,” said Gonzalo Gallegos, a State Department spokesman. “We’re looking at conditions, not calendars here.”

“We’re making progress and are committed to departing, as evidenced by the fact that we have transferred over half of the country’s provinces to provisional Iraqi control, and we’re planning on removing the fifth and final surge brigade at the end of the month here, if things go according to plan,” he told reporters.

Al-Maliki has instructed his negotiating team to harden its position in recent days because he thinks the Bush administration is eager to sign an agreement before the fall elections, giving Iraq the chance to win a better deal, said a senior Iraqi Shiite official knowledgeable about the talks.

The official spoke on condition of anonymity because of the talks’ sensitivity.

Al-Rubaie, who spoke to reporters after meeting with Grand Ayatollah Ali al-Sistani in Najaf, a key player in Iraq’s politics, did not provide details on the proposed timeline.

But Ali al-Adeeb, a Shiite lawmaker and a prominent official in the prime minister’s party, told The Associated Press that Iraq was linking the proposed timeline to the ongoing return of various provinces to Iraqi control.

The proposal stipulates that once the U.S. transfers security authority back to Iraq in all 18 provinces, American-led forces would then withdraw from all cities nationwide.

After that, Iraq’s security situation would be reviewed jointly every six months, for three to five years, to decide when U.S.-led troops would pull out entirely, al-Adeeb said.

So far, the United States has handed control of nine of 18 provinces to Iraqi officials.

“This is what the Iraqi people want, the parliament and other Iraqi leaders,” said al-Adeeb.

The proposal, as outlined by al-Adeeb, is phrased in a way that would allow Iraqi officials to tell the Iraqi public that it includes a specific timeline for a U.S. withdrawal, with specific time periods mentioned.

However, it also would provide the United States some flexibility on timing because the dates of the provincial handovers are not set.

The U.S. military recently delayed the handover of Anbar and Qadisiyah provinces, for example, blaming bad weather, and new dates have not been released.

The issue of a withdrawal timeline has been a key controversy in the United States.

It is at the center of the debate between Democrat Barack Obama and Republican John McCain as the presumptive presidential nominees look ahead to the general election.

Obama has promised to remove U.S. combat forces from Iraq within 16 months of taking office although he has said that could slip. The idea is opposed by McCain, who is against a specific timeline. Obama is expected to visit Iraq this month.

In Iraq, anti-American Shiite cleric Muqtada al-Sadr has kept the issue in the foreground î and put pressure on the government î by consistently calling for an immediate withdrawal of U.S. troops.

Sticking to that position, Sadrist lawmaker Falah Hassan Shanshal reacted coolly to the Iraqi government’s negotiations.

“We reject signing anything with the U.S. before the withdrawal of the occupation forces,” Shanshal said.