BAGHDAD, Iraq — U.S. and Iraqi troops battled insurgents house-to-house today, the third day of an assault against al-Qaida-led insurgents in a town near the Syrian border. The U.S. command reported the first American death in the operation.

In Baghdad, a leading Sunni Arab politician, Adnan al-Dulaimi, called today for a halt to U.S. and Iraqi military operations against cities in order to encourage disaffected Sunnis to join the political process and vote in national elections next month.

The U.S. commander of the joint force, Col. Stephen Davis, said that by late Sunday, his troops had moved "about halfway" through Husaybah, a market town along the Euphrates River about 200 miles northwest of Baghdad.

At least 36 insurgents have been killed since the assault began Saturday, and about 200 men have been detained, Davis told The Associated Press by telephone. He did not give a breakdown of nationalities of the detainees. Many were expected to be from a pro-insurgent Iraqi tribe.

A Marine was killed by small arms fire in Husaybah on Sunday, the military said. The New York Times, which has a journalist embedded with the U.S. forces, reported that three Marines were also wounded Sunday.

Elsewhere, an American soldier was killed Sunday by a roadside bomb near Tikrit, the U.S. command said. The latest deaths raised to at least 2,047 the number of members of the U.S. military who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

U.S. officials have described Husaybah, which used to have a population of about 30,000, as a stronghold of al-Qaida in Iraq, which is led by Jordanian extremist Abu Musab al-Zarqawi. Husaybah is a main entry point for foreign fighters, weapons and ammunition entering from Syria. From Husaybah, the fighters head down the Euphrates valley to Baghdad and other cities.