U.S. Secretary of Defense Robert Gates on Tuesday linked the pullout of troops from Afghanistan to the situation in the militancy-ridden country.

"The transition of security responsibility that begins in July 2011 will be gradually and based on condition on the ground," he told a joint press conference after meeting President Hamid Karzai at his Palace.

He also added that, "We would proceed this, province by province as conditions permits."

This is the first visit of the Defense Secretary after President Obama unveiled new strategy for Afghanistan last Wednesday in which he announced sending in extra 30,000 troops to the war-torn country to bolster war on militants.

There are already more than 100,000 NATO-led troops in Afghanistan with 68,000 of them Americans fighting Taliban-led insurgency and al-Qaeda operatives.

"Our troops are here only as long as it takes to help you defeat your enemies, we will fight by your side until Afghan forces are large enough and strong enough to secure the nation on their own as they have already done in Kabul," Gates said.

"Our relationship with Afghanistan is long term commitment as security improves and we begin turning on the responsibly to Afghans, but our relationship with other areas will be grown especially on economic and development," he further added.

Assuring Washington's firm support, he noted that "President Obama has said repeatedly our government will not again turn back on this country or the region." But added, "the Americans commitment was not open-ended."

"Afghanistan is looking forward to taking the lead in securing the nation within five years but our nation would need financial help to pay the salaries and equip the growing security forces," President Karzai said for his part at the joint press conference.

Calling on international community for more support, Afghan President said that "it will not be able to sustain a force of that nature and capability with its own resources."