WASHINGTON, June 21: US President George W. Bush engaged in long-distance diplomacy on Tuesday to defuse tensions between two of its close allies in the war against terror, urging both Pakistan and Afghanistan to exercise restraint.

Minutes after Mr Bush called President Pervez Musharraf, the Pakistani leader called his Afghan counterpart Hamid Karzai and both leaders pledged to continue their cooperation in the war against terror.

Mr Bush’s telephone call came a day after Afghanistan claimed it had arrested three Pakistani nationals for allegedly plotting to assassinate former US Ambassador Zalmay Khalilzad who has now been sent to Iraq as the new US envoy in Baghdad.

Pakistan reacted strongly to the allegation asking Afghanistan to produce any evidence it had or stop making false claims.

Afghanistan reacted to Pakistan’s rejection by claiming that Islamabad was supporting Afghan insurgents.

Afghan presidential spokesman Jawed Ludin said the country had suffered a spate of attacks in recent weeks committed by terrorists who had allegedly entered from Pakistan, including a suicide bombing at a mosque in Kandahar that had killed 20 people.

Pakistani foreign office spokesman Jalil Abbas Jilani said he was ‘surprised’ by Mr Ludin’s comments and reminded him that President Karzai also had acknowledged Islamabad’s contribution to the fight against terrorism.

As tensions mounted, President Bush telephoned Gen Musharraf and, according to the US officials, discussed the war on terrorism with him.

The telephone discussion, lasting about 15 minutes, also covered relations between India and Pakistan and US-led efforts to promote democracy in Afghanistan, US officials said.

White House press secretary Scott McClellan was asked if the two leaders had discussed CIA director Porter Goss’ remarks that he had an ‘excellent idea’ about where Osama bin Laden was hiding. Mr McClellan said that Mr Goss “was referring to the general area he’s believed to be in. If we knew exactly where he was, we would go get him.”

US and Afghan officials have recently said that they believe Osama is hiding in the tribal region along the Pakistan-Afghan border.

Asked if the US was receiving 100 per cent cooperation from the countries that Mr Goss believed Osama was hiding in, Mr McClellan said: “We are receiving good cooperation from the government of Pakistan.”

He said Pakistan was America’s partner in the global war on terrorism and had been working with the US to go after the Al Qaeda and Taliban remnants. “They understand the importance of staying on the offensive and going after the terrorists to disrupt plots and prevent them from carrying out the attacks,” he added.

Mr McClellan said President Musharraf also recognized the importance of going after those terrorists and bringing them to justice before they could do harm. “So we appreciate the work that the government of Pakistan is doing to partner with us in the global war on terrorism,” he added.

Meanwhile, in a statement issued in Kabul and also distributed by the Afghan Embassy in Washington, Afghan officials said President Musharraf had telephoned President Karzai to discuss the situation.

The statement reflected a major change of tone, indicating that Mr Bush’s peace effort had a positive impact on Kabul and Islamabad where a similar statement also emphasized the need for continuing Pakistan-Afghan cooperation against terrorism.

“The two presidents discussed matters of bilateral interest, including security developments in the context of Afghanistan’s preparations for the parliamentary elections in September,” said the official Afghan statement.

“President Musharraf assured President Karzai of Pakistan’s continued support and cooperation in the fight against terrorism. President Karzai appreciated Pakistan’s role in the war against terrorism and emphasized the need for continued and further cooperation in ensuring security and fighting the menace of terrorism,” it said.

Both presidents agreed to strengthen engagement and cooperation in the security area between the two governments, Afghan officials said. The statement issued in Islamabad said the two leaders discussed matters of bilateral interest as well as developments of regional and international significance.

The Afghan leader briefed the president on preparations for the upcoming parliamentary election in Afghanistan and Gen Musharraf assured his Afghan counterpart of Pakistan’s continued support and cooperation in the fight against terrorism, the statement said. While Pakistan condemned terrorism “in all its forms and manifestations, the Afghan leader appreciated Pakistan’s role in the fight against terror.”

“There was complete satisfaction on both sides at the steady growth in bilateral relations. Cooperation in diverse fields was well set to acquire further strength and substance. No effort would be spared to maintain the upswing,” the statement said.