Giving up the fight in Afghanistan would put the United States and its allies in danger by allowing the war-torn country to turn back into a base for attacks, U.S. Senator John McCain said.

Appearing on ABC's Good Morning America in New York on Wednesday, McCain urged President Barack Obama Wednesday to approve, without delay, a call by Gen. Stanley McChrystal, the U.S. and NATO commander in Afghanistan, for 40,000 more combat troops.

"Time is not on our side," McCain said. "So we need a decision pretty quickly. I think history is pretty clear that when the Taliban took over, it became a base for attacks on the United States and our allies."

McCain's remarks came on the same day that Obama was to meet at the White House with members of his national security team including Vice-President Joe Biden, Secretary of State Hillary Rodham Clinton and Defence Secretary Robert Gates to discuss Afghan strategy.

On Tuesday, Obama met with NATO Secretary General Anders Fogh Rasmussen to talk about a possible new strategy in Afghanistan.

Obama currently is considering U.S. options in Afghanistan, which include boosting military strength there to try to neutralize the Taliban and other extremists and pursuing a new strategy of rooting out al-Qaeda militants in neighbouring Pakistan.

The latter option would involve fewer troops and more unmanned drones and special forces units. NATO contributes roughly two-thirds of the more than 100,000 international troops in Afghanistan, including 68,000 from the U.S. and more than 3,000 from Canada.

With files from The Associated Press