President Barack Obama says the United States is very worried about al-Qaida terrorism and extremism in Yemen.

Obama says Yemen is drawing foreign terrorists who once might have gone to Pakistan's border area, where insurgents gather to fight NATO forces in Afghanistan.

A suicide bomber blew himself up at a military parade rehearsal Monday in Yemen's capital, killing 96 soldiers in one of the deadliest attacks in the city in years.

Al-Qaida's Yemen branch claimed responsibility for the attack.

Obama says that despite U.S.-backed political progress in Yemen, the country is poor and unstable, and at risk from extremism inside and outside its borders.

He spoke at a news conference that closed a NATO summit on Afghanistan.