WASHINGTON, Sept 4: The US administration is officially refusing to comment on a cross-border raid into Pakistan that killed at least 15 people, but unnamed US officials are confirming that American troops entered Pakistan to target extremists and may continue to do so.

“In regards to the reports about that incident, we have not commented, and I won’t today,” White House spokeswoman Dana Perino told reporters on Thursday. “I’m just not going to comment on the incident in any way.”

At the State Department, Secretary Condoleezza Rice made almost identical comments, saying: “I don’t have anything for you on Pakistan except to say that, obviously, we are working very closely with the civilian government there, the newly democratically elected, civilian government.”

Asked why was she reluctant to comment on the reported US strike, Ms Perino replied: “All I can tell you is that I am going to decline to comment on reports about that incident.”

But the US media, from newspapers to television and radio stations, are all quoting senior US officials as saying that American commandos entered Pakistan on Wednesday to attack an Al Qaeda target near Angoor Adda.

They also warned that the United States might conduct similar raids in future as well if it had “actionable intelligence” about the presence of Al Qaeda or Taliban commanders in a certain area.

Unnamed Pentagon officials told the US media that US Special Forces had conducted the raid, focusing on a specific target in South Waziristan. The officials also emphasised Washington’s desire to destroy militant safe havens in Pakistan’s tribal areas.

The officials said that the decision to send US ground troops inside Pakistan marked a return to tactics used by the American military soon after the Afghanistan invasion.

In recent years, the United States has tended to limit its cross-border actions to artillery and air strikes against militants.

Pentagon spokesman Lt-Col Patrick Ryder told reporters there was “nothing to provide” regarding the incident. US Central Command officials also declined to comment.

Islamabad has denounced the raid as ‘shameful’ and ‘unjustified’ but said it would remain a US ally in the war on terror.

In Washington, Pakistan Embassy conveyed Islamabad’s concern to “the highest levels of the State Department,” embassy sources said.

“Unilateral actions that enraged the Pakistani people will not help the US and Nato in the war against terror,” Ambassador Husain Haqqani told Dawn.

“For the war effort to succeed, cooperative arrangements between Pakistan, Afghanistan and Nato need to be strengthened, instead of actions violating the sovereignty of an American ally and partner.”

At the White House, spokeswoman Perino stressed the need to “increase coordination and cooperation” between Pakistan and the US-led forces.

US officials have often used this phrase to convey their dissatisfaction with Pakistan’s failure to stop cross-border incursions into Afghanistan.

But Ms Perino kept a conciliatory tone while talking about Pakistan’s efforts in the war on terror, saying that will continue to support Islamabad in this war as “we work to fight against the Taliban in a coordinated way”.

She also underlined the close ties between Washington and the new government in Islamabad. “I will reiterate is that we’ve been working closely with the new civilian government of Pakistan that is feeling its way and working to establish itself,” Ms Perino said.

Several major US newspapers and television channels reported on Thursday that the raid was intended to warn the militants not to take advantage of political uncertainty in Pakistan.

ABC News reported that US officials “privately called (the Angoor Adda raid) a successful operation.”

Bruce Riedel, a former senior official at the White House National Security Council and former CIA officer, told The Washington Times that the situation “is going to complicate an already complicated and unhappy relationship between Washington and Islamabad.”

“Both sides feel the other side is misleading them and not doing all they can on their end but blaming the other for what happens,” said Mr Riedel, who is author of an upcoming book, “The Search for Al Qaeda: Its Leadership, Ideology and Future. “It should be remembered in all this at the end of day Pakistan has enormous amount of leverage to make life unpleasant for the US and coalition.”

Mr Riedel said that “80 per cent or more” of US and coalition support and logistics for troops came into Afghanistan via Pakistan and that without that support the international forces capabilities in Afghanistan would be hampered.