The number of American troops in Iraq has dropped below 100,000 for the first time since the 2003 U.S.-led invasion in a clear signal the U.S. is wrapping up its nearly seven-year war to meet a deadline for leaving the country, the U.S. military said Tuesday.

The troop reduction comes at a critical time in Iraq as Washington questions the shaky democracy's ability to maintain security in the tense period surrounding March 7 parliamentary elections. Those concerns have only grown with a decision by a vetting committee to bar hundreds of candidates from running because of suspected ties to Saddam Hussein's outlawed Baath Party.

The U.S. military plans on maintaining its current 98,000 boots on the ground in Iraq through the elections, 1st Lt. Elizabeth Feste, an army spokeswoman in Baghdad, told The Associated Press.

That's in line with what Gen. Ray Odierno, the top U.S. commander in Iraq, has said would remain in place until at least 60 days after the election — a period during which he believes Iraq's new government will be at its most vulnerable.

International observers fear that tension between the Shiite-dominated government and minority Sunnis may spill into the streets, re-igniting sectarian violence that could threaten the planned U.S. withdrawal.

President Obama has ordered all but 50,000 troops to leave Iraq by Aug. 31, 2010, with the remainder pulling out by the end of next year under an Iraqi-American security agreement.

"The withdrawal pace remains on target for about 50,000 at the end of August 2010," Feste said.

Iraqi Prime Minister Nouri al-Maliki is running for re-election on a campaign promise to make Iraq independent from U.S. military help. At a campaign rally Tuesday, he signaled that the U.S. cannot expect to use Iraq as a launching pad for military action in the Middle East.

He also cited a strong desire to improve relations with nations bordering Iraq that were seen as enemies during Saddam Hussein's regime. Al-Maliki's comments appeared to be directed at Iran, although he did not mention any countries by name.

"We also confirm to all our neighboring and friendly countries that our constitution stipulates to not let the Iraqi territories be a springboard to harm security and interests of any state," al-Maliki told supporters at a Baghdad hotel.

A senior U.S. military official said Tuesday he expected the number of forces in the country by 2011 to be whittled down to between 20,000 and 30,000, with those remaining forces out by the end of 2011.

Troop levels have fluctuated dramatically throughout the nearly seven-year war, shifts that generally reflected a change in U.S. strategy.

During the height of the invasion in May 2003, about 150,000 U.S. forces were in Iraq. But that number quickly dropped off by January 2004, with American troops moving from a combat to occupation role.

But by October 2005, the number climbed back up to 160,000 as the insurgency took hold in Iraq, according to the Pentagon. At the peak of the troop buildup in October 2007, there were roughly 170,000 troops on the ground as part of a counterinsurgency strategy known as the "surge."

Though the U.S. military has heavily touted the decline in overall violence and the success of Iraq's security as the reason for its withdrawal, it also has repeatedly warned about an increase in attacks before the election.

Commanders have said they do not expect violence to increase to levels that would require the return of U.S. troops onto the streets of Iraq's cities. Privately, though, many question whether Iraq can keep the lid on violence once the U.S. pulls out completely by the end of 2011.

A series of security lapses in recent months has allowed insurgents to repeatedly launch large-scale suicide bombing attacks against government sites as well as symbols of Western influence, such as hotels. Hundreds were killed in the attacks.

Security forces have been the target of near daily, smaller attacks by insurgents seeking to derail public confidence.

On Tuesday, a string of bombs targeted Iraqi army patrols and a police crime lab in Mosul, 225 miles (360 kilometers) northwest of Baghdad, an area where insurgents retain a foothold despite a sharp drop in violence across the rest of the country.

In the first attack, a car bomb exploded outside a side entrance of the police crime lab in Mosul, said Lt. Col. Salim Ibrahim, an area commander. It killed two people and wounded seven, including five police officers, he said.

Later, two roadside bombs struck separate Iraqi army patrols in eastern Mosul, killing two soldiers, an army official said, speaking on condition of anonymity because he wasn't authorized to release the information. Five people, including three civilians, were wounded.

In recent weeks in and around Mosul, security checkpoints have been attacked in drive-by shootings and the motorcade of the provincial governor was attacked.

Gunmen also opened fire Tuesday on two Christian college students waiting at a bus stop in Mosul, killing one and wounding the other, a police official said, speaking on condition of anonymity because he was not authorized to release the information.