Washington, Mar 29 (PTI): US president Barack Obama, who made a surprise visit to Kabul and met president Hamid Karzai, has vowed to deny al-Qaeda safe haven and reverse Taliban's momentum in Afghanistan.

"We are going to disrupt and dismantle, defeat and destroy al-Qaeda and its extremist allies. That is our mission. And to accomplish that goal, our objectives here in Afghanistan are also clear. We're going to deny al-Qaeda safe haven. We're going to reverse the Taliban's momentum," Obama said in his address to US soldiers at the Bagram airfield.

The US President last night reiterated his country's support to strengthen the capacity of Afghan forces and the Afghan government so that they could take responsibility and gain confidence of their own people.

Al-Qaeda and their extremist allies were not only a threat to the people of Afghanistan and America, but also a threat to the people all around the world, he said.

Recollecting 9/11 attack, Obama said this was the region where the perpetrators of the crime, al-Qaeda, still had their leadership.

"Plots against our homeland, plots against our allies, plots against the Afghan and Pakistani people are taking place as we speak right here," the US president said.

"If this region slides backwards, if the Taliban retakes this country and al-Qaeda can operate with impunity, then more American lives will be at stake. The Afghan people will lose their chance at progress and prosperity. And the world will be significantly less secure," he said.

Apart from the military effort to take the fight to the Taliban, Obama said his Afghan policy included civilian effort which aimed to improve daily lives of Afghans, combat corruption; and a partnership with Pakistan and its people.

"We can't uproot extremists and advance security and opportunity unless we succeed on both sides of the border," he said.

Across the border, the US President said Pakistan has mounted a major offencive against terrorism in its territory.

"We've seen violent extremists pushed out of their sanctuaries. We've struck major blows against al-Qaeda leadership as well as the Taliban's. They are hunkered down. They're worried about their own safety," he said, adding America would be more secure with these efforts.

The United States would continue to pursue the Taliban and al-Qaeda as it was required to ensure the safety of American families back home, he added.