President Barack ObamaU.S. President Barack Obama says he will decide on whether or not to send more troops to Afghanistan in a matter of weeks. The White House is adding on more high level meetings to discuss possible changes in strategy.

The Afghan review has been going on for several weeks, with the president spending hours huddled behind closed doors with members of his national security team.

They will continue their deliberations on Wednesday, and an additional session is expected next week.

The process is going on longer than expected. But President Obama says he is taking the time needed to get the decision right. "I would expect that we will have a completion of this current process in the coming weeks," he said.

He emphasizes that the discussions are not just about troop levels. When he announced his new Afghan policy in March, he stressed then that security, political and development considerations must go hand in hand.

The president says that is still the case. "The military security that is provided and our ability to train Afghan forces is one element of it. Another element of it is making sure that we are doing a good job in helping build capacity on the civilian side in areas like agriculture and education," he said.

Mr. Obama spoke to reporters at the end of talks with Spanish Prime Minister Jose Luis Rodriguez Zapatero. He said America's mission in Afghanistan has not changed. "Our principle goal remains to root out al-Qaida and its extremist allies that can launch attacks against the United States or its allies," he said.

The president is now weighing several options.

The U.S. commander in Afghanistan, General Stanley McChrystal, is urging the administration to deploy a substantial number of additional troops.

Vice-President Joe Biden is advocating a different approach - one that relies more on elite anti-terrorism units and air strikes to target al-Qaida.