WASHINGTON — Sending thousands more American troops into Iraq or Syria in a bid to accelerate the defeat of the Islamic State group would push U.S. allies to the exits, create more anti-U.S. resistance and give up the U.S. military’s key advantages, Defense Secretary Ash Carter said in an Associated Press interview.

Speaking from his Pentagon office overlooking the Potomac River on Wednesday, Carter said he favors looking for ways to speed up the counter-IS campaign, which administration critics including the president-elect, Donald Trump, have called slow-footed and overly cautious.

But he outlined numerous reasons why he believes strongly in the current approach of letting local Iraqi and Syrian forces set the pace.

“If we were to take over the war in Iraq and Syria entirely ourselves, first of all, in the near term it would be entirely by ourselves, because there is no one else volunteering to do that,” he said. “We could get past that. But secondly, we would risk turning people who are currently inclined to resist ISIL” or to join ranks with the coalition, “potentially into resisting us, and that would increase the strength of the enemy.”

Taking over the war also would amount to “fighting on the enemy’s terms, which is infantry fighting in towns in a foreign country,” he said. While U.S. troops can do that, it would not leverage the U.S. military’s biggest strengths, which are special operation forces, mobility, air power and intelligence-gathering technologies — “exquisite capabilities that no one else has,” he said — to enable local troops to do the fighting and own the outcome.