A Hawai'i Marine and an Afghan soldier were killed Thursday in eastern Afghanistan during a U.S.-led offensive northwest of Asadabad, a violence-prone region where militants have vowed to disrupt parliamentary elections scheduled for Sept. 18.

The 22-year-old Marine from the Houston area, with the 2nd Battalion, 3rd Marine Regiment out of Kane'ohe Bay, was taking part in an effort to clear the way for successful elections, a U.S. official said. Details of his death were not provided.

His family has been notified, but policy requires 24 hours to pass for privacy before the name can be released by the military to the public, officials said.

Lt. Col. James E. Donnellan, the commander of about 1,000 Hawai'i Marines and sailors in Afghanistan, said the latest losses "will only strengthen our resolve to complete the mission."

Lance Cpl. Kevin B. Joyce, a 19-year-old Marine from Klagetoh, Ariz., assigned to the 2nd Battalion, 3rd Marine Regiment, drowned in floodwaters of the Pech River on June 25 when a cliffside road he was driving on gave way, throwing three Marines out of a vehicle.

The 2/3 Marines relieved the Hawai'i-based 3rd Battalion, 3rd Marine Regiment in Afghanistan in June. The 3/3 Marines, known as "America's Battalion," lost two Marines during their eight-month tour.

The Marines and Afghan troops launched an offensive this week in the remote Korengal Valley, where five Hawai'i-based Navy SEALs were killed in June.

All five SEALs died in connection with an ill-fated reconnaissance mission and failed rescue June 28 in the rugged mountainous region.

A total of 19 U.S. servicemembers died in connection with the missions that day when a helicopter was hit by a rocket-propelled grenade. Only one SEAL was found alive.

U.S. officials said Korengal Valley, in eastern Kunar Province near the Pakistani border, held hundreds of Afghan rebels and extremists from Pakistan, Saudi Arabia and Chechnya intent on disrupting voting.

"We want them running for their lives way up in the hills where they can't attack polling stations," Capt. John Moshane of the 2nd Battalion, 3rd Marine Regiment, said at the start of the operation. "We want to isolate them from the community."

Hawai'i Marines at a 2/3 base at Jalalabad have been experiencing a heat wave, with daily temperatures exceeding 100 degrees.

Reach William Cole at wcole@honoluluadvertiser.com.