Washington, Nov 20 - Noting that a "cross border fertilisation of terrorism" is preventing both Pakistan and Afghanistan to defeat the forces threatening them, Secretary of State Hillary Clinton wants the two countries to work together to defeat terrorism.

"We know that there is a cross-border fertilisation of extremism and terrorism," Clinton who was in Afghanistan for the inauguration of President Hamid Karzai's second term told the local Azadi Radio in an interview.

"Afghanistan cannot get control over its territory and defeat the Taliban if they can go across the border into Pakistan as a safe haven," she said according to the transcript of the interview released here Thursday by the State Department.

Similarly, Pakistan cannot root out the people that threaten them and their government if they can seek refuge across the border in Afghanistan, she said. "That's why we look at Afghanistan and Pakistan together when it comes to this fight against terrorism."

Having recently visited Pakistan, Clinton said she knows that the Pakistani military is working very hard in South Waziristan, and they do have to have priorities as to how they will spend their resources and their troops.

"But we will continue to press them to go after all of the extremists in Pakistan, some of whom target Pakistan, some of whom, as you know, target Afghanistan. And we think there has to be an effort to root out the extremists in Pakistan who threaten Afghanistan," she said.

"So that is the message that I took to Pakistan when I was there a few weeks ago. It's the message that I continue to stress with our friends in Pakistan," Clinton said.

In another interview to BBC, Clinton said the US has a national security interest in going after the syndicate of terror that Al Qaeda has helped to pull together, which includes elements of the Afghan and Pakistan Taliban.

"It is a direct threat to the US, to our allies, our interests, our values.

"And we are determined to defeat Al Qaeda," she said. (IANS)