Pakistan said Thursday it was not warned about a suspected U.S. missile strike in its northwest that came the same day a top American official assured Pakistani leaders of U.S. respect for its sovereignty.

The reported attack will likely fuel anger in Pakistan over a surge in cross-border operations by U.S. forces — including a Sept. 3 ground assault — that has strained the countries' seven-year anti-terror alliance.

Washington has long been concerned about Pakistani tribal regions near the Afghan border that militants use as bases from which to plan attacks in Afghanistan.

Two intelligence officials told The Associated Press that on Wednesday several missiles hit a compound in South Waziristan used by Taliban militants and Hezb-i-Islami, another group involved in escalating attacks on U.S. and government troops in neighboring Afghanistan.

They said informants in the area reported that six people were dead and three more wounded. Both officials spoke on condition of anonymity because they are not authorized to speak to the media.

The strike came as the chairman of the U.S. joint chiefs of staff, Adm. Mike Mullen, was in Pakistan visiting with the prime minister, the army chief and other officials.

The visit came following official Pakistani protests over the ground assault, which also occurred in South Waziristan.

According to a statement from the U.S. Embassy, Mullen said the U.S. was committed to respecting Pakistan's sovereignty and sought more cooperation in the war on terror.

During a press conference Thursday, Pakistani Foreign Minister Shah Mahmood Qureshi, who was among those who met with Mullen, said Pakistani officials "were not informed" of the alleged missile strike.

He said Mullen's assurances combined with the suspected missile strike indicated "an institutional disconnect" on the U.S. side.

"My understanding of the rules of engagement is that no foreign troops will be permitted to operate in Pakistan," Qureshi said. "If there is action required inside our territory, it will be carried out by our forces."

"Our stance is that we should cooperate with each other, and such incursions cannot improve the atmosphere, and rather they will deteriorate it, and will be counterproductive," he said.

U.S. Embassy spokesman Gonzalo Gallegos declined to comment Thursday.