WASHINGTON, June 11: The United States said on Wednesday that a US military operation which killed 11 Pakistani soldiers was first coordinated with the Pakistan Army.

Also on Wednesday, a media report quoted Pakistan’s envoy to Washington as saying that US leaders had warned Islamabad that if the United States suffered an attack that was traced back to Pakistan Washington would retaliate.

“Those (statements) have been made,” Ambassador Hussain Haqqani told editors and reporters at The Washington Post. “We want to make sure that it doesn’t come to that.”

Meanwhile, a spokesman for the US-led Nato forces in Afghanistan confirmed the clash but said that coalition forces had come under fire “during an operation that had been previously coordinated with Pakistan”.

Reports in the US media said the fighting erupted when Afghan troops tried to establish a checkpost near the village area of Sheikh Baba in the Mohmand tribal region.

First Lt. Nathan Perry, a spokesman for the coalition forces, told Dawn that coalition forces received small arms and rocket-propelled grenade fire from an unknown number of anti-Afghan forces approximately 200 meters inside the Kunar province.

“Coalition forces returned fire in self-defence,” he added.

“Shortly after the attack began, coalition forces informed the Pakistan Army that they were being engaged by anti-Afghan forces in a wooded area near the Gora Prai checkpoint,” he said.

“At the same time, an unmanned aerial system also identified anti-Afghan forces firing at coalition forces. In self-defence, coalition forces fired artillery rounds at the militants.”

Lt Perry claimed that an unmanned aerial system identified additional anti-Afghan forces joining the attack against the coalition forces.

“While maintaining positive identification of the enemy, close-air support was then used by coalition forces to gain fire superiority until the threat was eliminated,” said the spokesman.

“At no time did coalition ground forces cross into Pakistan.”

Asked if missiles and artillery shells fired by coalition forces hit targets inside Pakistan, the spokesman said: “Yes, that’s correct.”

Lt Perry said US military officials had already ordered an investigation of this incident.

US-led Nato forces have launched several air strikes inside Pakistan’s tribal areas over the last year but this is the first time that the Pakistan Army has directly blamed US-led Nato forces for killing its soldiers.

On Tuesday, Admiral Michael Mullen, chairman of the US Joint Chiefs of Staff, warned that Al Qaeda leaders operating in Pakistan’s tribal areas were planning new terrorist attacks against the United States and urged Islamabad to eliminate their sanctuary.

Admiral Mullen called upon Pakistani authorities to enforce any deals they strike with tribal leaders in the Fata and to require not only the expulsion of Al Qaeda but also a halt to the flow of insurgents across the border into Afghanistan.

In his interview to the Post, Ambassador Haqqani listed new conditions Pakistan would impose in any deal with militants. Fighters will now have to pledge not to launch attacks in either Pakistan or Afghanistan. All foreign fighters in the tribal areas must be expelled. And extremists must promise not to give safe haven to any group targeting any of Pakistan’s allies, including the United States.

Mr Haqqani also offered to overcome any misgivings that the US might have about sharing intelligence with Pakistan.