WASHINGTON (Reuters) - The United States could not have stopped the humanitarian crisis in Syria with military strikes, President Barack Obama said in a television interview airing on Friday, and said U.S. troops had reached their limits after long wars in Iraq and Afghanistan.

Obama was asked in an interview with CBS Evening News anchor Scott Pelley whether he regretted not applying U.S. force in Syria, where the three-year civil war has killed more than 140,000 people and displaced millions.

"It is, I think, a false notion that somehow we were in a position to, through a few selective strikes, prevent the kind of hardship that we've seen in Syria," Obama said.

"It's not that it's not worth it. It's after a decade of war, you know, the United States has limits," he said.

Obama said the United States would have a hard time committing to putting troops on the ground in Syria, a commitment he said could have lasted "perhaps another decade."

American troops have been involved in a decade of war in Iraq and Afghanistan.

"And it's not clear whether the outcome in fact would have turned out significantly better," Obama said.

The interview was recorded before Obama flew to Saudi Arabia where he discussed the Syrian conflict with Saudi king Abdullah.

(Reporting by Roberta Rampton; Editing by Ken Wills)