Militants opened fire Monday on a convoy carrying U.S. and Pakistani military officials near the Afghan border, killing one American and a Pakistani soldier, the Pakistani army spokesman said.

Four Americans and four Pakistani soldiers were wounded.

Maj. Gen. Waheed Arshad said unidentified "miscreants" -- a word usually used by Pakistani officials to describe Islamic militants -- fired at the convoy carrying military officials who attended a meeting in the northwestern town of Teri Mangal.

"Efforts are being made to determine from where the firing came from and who carried it out. The area has been cordoned (off)," he said.

Afghan military officials also attended the talks to discuss recent fighting between Afghan and Pakistani forces that Kabul said killed at least 13 people inside Afghanistan -- inflaming already poor relations between Pakistan and Afghanistan.

NATO's International Security Assistance Force in Afghanistan confirmed one ISAF soldier was killed and four wounded. According to policy, it did not give their nationalities. It said they "were ambushed by unknown assailants."

NATO said its soldiers were being treated in Afghanistan.

Rahmatullah Rahmat, governor of the Afghan border province of Paktia, said he, U.S. military advisers and Afghan army leaders traveled by helicopter to Pakistan for the meeting.

He said that after the meeting ended, gunmen opened fire as the group headed toward their helicopters. Rahmat said two Americans died and two were wounded.

He said American soldiers returned fire.

Pakistan has ordered a high-level inquiry into the incident, Arshad said. He denied reports from the Afghan Defense Ministry spokesman that a Pakistani soldier had opened fire on the American troops.

Islamic militants, including supporters of the Taliban and Al Qaeda, are active in the lawless border region.