WEST POINT - US President Barack Obama said Tuesday that new Al-Qaeda attacks were "being plotted as I speak," as he announced the deployment of another 30,000 US troops to Afghanistan.

"I make this decision because I am convinced that our security is at stake in Afghanistan and Pakistan. This is the epicenter of the violent extremism practiced by al Qaeda," Obama said, unveiling his new strategy for turning around the war in Afghanistan.

"It is from here that we were attacked on 9/11, and it is from here that new attacks are being plotted as I speak. This is no idle danger; no hypothetical threat."

Addressing the American nation from the prestigious West Point military academy, Obama said the US authorities had in the last few months apprehended extremists sent from Afghanistan and Pakistan to the United States to "commit new acts of terror."

"This danger will only grow if the region slides backwards, and Al-Qaeda can operate with impunity. We must keep the pressure on Al-Qaeda, and to do that, we must increase the stability and capacity of our partners in the region."