WEST POINT, New York: President Barack Obama said on Tuesday he is sending 30,000 more US troops to Afghanistan by next summer to speed the battle against the Taliban and plans to start bringing some home in 18 months.

US Army cadets look on before US President Barack Obama addressed the US Military Academy in West Point, New York, December 1, 2009.

The accelerated timetable Obama unveiled in a high-stakes speech surprised some Pentagon planners who expected a 12- to 18-month period for deploying forces to bolster the 68,000 US troops already in the war zone.

"As commander-in-chief, I have determined that it is in our vital national interest to send an additional 30,000 US troops to Afghanistan. After 18 months, our troops will begin to come home," Obama told cadets at the US Military Academy in West Point, New York.

These US troops, plus an expected extra contingent from NATO allies, Obama said, "will allow us to accelerate handing over responsibility to Afghan forces and allow us to begin the transfer of our forces out of Afghanistan in July of 2011."

And he sought to reassure NATO allies and the leaders of Afghanistan and Pakistan that he was not abandoning the war effort, while pressuring them to make sure they hold up their end of the bargain.

Obama said he did not make his decision lightly.

"If I did not think that the security of the United States and the safety of the American people were at stake in Afghanistan, I would gladly order every single one of our troops home tomorrow," he said.

Obama said he was confident the allies of the United States would also send reinforcements.

"Our friends have fought and bled and died alongside us in Afghanistan. Now, we must come together to end this war successfully," he said.

"For what's at stake is not simply a test of NATO's credibility. What's at stake is the security of our allies and the common security of the world."