KABUL, Afghanistan - Afghan President Hamid Karzai said Thursday his nation's youth will stand up and defend the country as the U.S. begins to pull troops out, while the Taliban promised to fight as long as foreign soldiers remain.

Karzai spoke briefly from the presidential palace after U.S. President Barack Obama announced he would bring 33,000 U.S. troops home by next summer. Karzai thanked international troops for their support and said "the people of Afghanistan will be protecting their homeland."

"The transition of the security and the withdrawal of the foreign troops from Afghanistan means the Afghan forces must be strengthened," Karzai said.

The U.S. and its allies have set Dec. 31, 2014, as a target date for ending the combat mission in Afghanistan.

The war has killed at least 1,500 members of the U.S. military and wounded another 12,000 since the war began in late 2001. The financial cost of the war has passed $440 billion and is on the rise, jumping to $120 billion a year.

Karzai, who has increased his criticism of the U.S.-led NATO force in recent months, said he and others welcomed the withdrawals as "a good measure."

Abdullah Abdullah, Karzai's former foreign minister who lost to him in Afghanistan's 2009 presidential election, cautioned the U.S. and NATO drawdowns needed to be gradual.

"The core Taliban group, their idea is to topple the system, to reverse the process," he said. "They will continue their struggle."

In a rare statement in English, Taliban spokesman Zabihullah Mujahid said the U.S. "must take serious steps to stop this pointless bloodshed."

The "Islamic Emirate of Afghanistan once again wants to make it clear that the solution for the Afghan crisis lies in the full withdrawal of all foreign troops immediately and until this ... happens, our armed struggle will increase from day to day," Mujahid said.

Meanwhile, French President Nicolas Sarkozy announced the progressive withdrawal of France's troops from Afghanistan on a timetable matching the American troop pullout that starts this summer. France currently has about 4,000 troops in the country.

British officials said Thursday the pace of U.K. troops withdrawals -- the second-largest contributor to the NATO force -- will be determined by conditions on the ground. About 450 British troops will leave Afghanistan this summer, Prime Minister David Cameron said.

On Wednesday night, Obama announced an initial drawdown of 10,000 troops in two phases, with 5,000 troops coming home this summer and 5,000 more by the end of the year. An additional 20,000-plus are to follow by September 2012.

As the war becomes increasingly unpopular as nears its 10th year, the U.S. and Afghan government have reached out and talked with Taliban emissaries. However, with the Taliban publicly saying fighting won't stop until foreign troops leave, it remains unclear if peace talks can be possible.

Fighting continued in the country after Obama's speech. In Kandahar province, NATO troops killed two Afghan border police officers Wednesday night they mistook for insurgents, said Abdul Ghani, the governor of Spin Boldak district. In a statement, NATO said it was aware of the report and was investigating.