Iraq's national security adviser said Tuesday his country will not accept any security deal with the United States unless it contains specific dates for the withdrawal of U.S.-led forces.

The comments by Mouwaffak al-Rubaie were the strongest yet by an Iraqi official about the deal now under negotiation with U.S. officials. They came a day after Iraq's prime minister first said publicly that he expects the pending troop deal with the United States to have some type of timetable for withdrawal.

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

U.S. officials had no immediate comment Tuesday on al-Rubaie's statement.

Al-Rubaie spoke to reporters after briefing Grand Ayatollah Ali al-Sistani in Najaf on the progress of the government's security efforts and the talks.

"Our stance in the negotiations underway with the American side will be strong ... We will not accept any memorandum of understanding that doesn't have specific dates to withdraw foreign forces from Iraq," al-Rubaie said.

He provided no details. 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 timetable proposal to the ongoing handover of various provinces to Iraqi control.

The Iraqi proposal stipulates that, once Iraqi forces have resumed security responsibility in all 18 of Iraq's provinces, U.S.-led forces would then withdraw from all cities in the country.

After that, the country's security situation would be reviewed 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 timetable and dates for a U.S. withdrawal.

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

Some type of troop status agreement between the United States and Iraq is needed to keep U.S. troops in Iraq after a U.N. mandate expires at year's end.

Iraq's government has felt increasingly confident in recent weeks about its authority and the country's improved stability. Iraqi officials have sharpened their public stance in the negotiations considerably in just the last few days.

Violence in Iraq has fallen to its lowest level in four years. The change has been driven by the 2007 buildup of American forces, the Sunni tribal revolt against al-Qaida in Iraq and crackdowns against Shiite militias and Sunni extremists.

In northern Baghdad Tuesday, guards opened fire, wounding 13 people when a crowd seeking aid payments for the poor, widows, orphans and disabled people became unruly, Iraqi officials said.

The U.S. military said a soldier had died from injuries sustained when a roadside bomb hit a troop convoy in Baghdad.

The U.S. military says five other soldiers were wounded in Tuesday's attack in the western Baghdad neighborhood of Amiriyah.