FBI Director Robert Mueller (searchwas meeting with senior Pakistani officials on Tuesday during a one-day visit to discuss counterterrorism efforts and other issues, U.S. and Pakistani officials said.

Mueller arrived early Tuesday at Chaklala (search), an air force base near the capital, said Terry White, a spokesman for the U.S. Embassy. It was not clear whether he would be meeting with President Pervez Musharraf (search).

Pakistan is a key ally in the war on terrorism. The country has arrested and turned over to Washington hundreds of Al Qaeda suspects, including Khalid Shaikh Mohammed, the alleged mastermind of the Sept. 11 terrorist attacks. Mohammed was arrested March 1 in Rawalpindi and is being held at an undisclosed location outside of Pakistan.

It was not clear what issues would top Mueller's agenda, but Pakistani officials said he would be holding talks on the progress hunting down Al Qaeda fugitives, including Usama bin Laden. Many intelligence officials believe bin Laden is hiding in the mountainous border region between Pakistan and Afghanistan.

White said the trip was planned well in advance.

"There's a range of issues that he is talking about with his counterparts, but it is not tied to any specific event," he said. "It's been scheduled for a while."

Mueller was in Yemen on Monday and met with that country's president, Ali Abdullah. Yemen is the ancestral home of bin Laden and the site of the October 2000 attack on the USS Cole that killed 17 American sailors.

Yemen's official news agency said Mueller's stop in Yemen was part of a regional tour "to discuss the global struggle against terrorism."

White said Mueller was traveling to several Middle Eastern and European countries on the trip. He was scheduled to leave Pakistan later Tuesday.