BAGHDAD — The U.S. military said today that a Marine was killed in fighting west of the capital, pushing the American death toll for July to at least 75, the lowest in eight months.

President Bush's nominee to head the Joint Chiefs of Staff, meanwhile, acknowledged that slow progress in Iraq is hurting America's credibility and emboldening Iran's regional ambitions.

While steady progress has been made on the military front, Iraq's political factions have made only limited headway in achieving reconciliation, said Navy Adm. Michael Mullen, who has been nominated to replace U.S. Gen. Peter Pace as the nation's top military officer.

Iraq's parliament shrugged off U.S. criticism and adjourned for a month, as key lawmakers declared there was no point waiting any longer for Prime Minister Nouri al-Maliki to deliver Washington-demanded benchmark legislation for their vote.

BAGHDAD — A U.S. helicopter went down today after coming under fire in eastern Baghdad, and the crew members were safely evacuated, the military said.The AH-64 Apache helicopter made a precautionary landing after facing ground fire east of the predominantly Shiite New Baghdad district, according to a statement.U.S. military spokesman Lt. Col. Christopher Garver said it was not known if the aircraft had been damaged.

GHAZNI, Afghanistan — Police discovered the body of a second South Korean hostage in central Afghanistan, and the Taliban threatened today to kill more captives if their demands were not met by a new deadline.South Korea pleaded with the international community to set aside the normal practice of refusing to cave into hostage-takers' demands, urging a peaceful resolution to the standoff. Relatives of some of the 21 remaining hostages appealed for U.S. help in freeing their loved ones.Afghan officials found the body of Shim Sung-min, 29, a former information technology worker who was volunteering with the South Korean church group on an aid mission to Afghanistan.He was killed Monday after two deadlines given by the Taliban demanding the release of insurgent prisoners passed with no action. Last week, the church group's leader, Pastor Bae Hyung-kyu, was fatally shot in unclear circumstances.