WASHINGTON — Americans are souring on President Barack Obama’s approach to fighting the Islamic State, according to an Associated Press-GfK poll that also found deep pessimism about U.S. prospects for success in Afghanistan and uncertainty about Obama’s plan to leave thousands of troops there when he leaves office.

More than 6 in 10 now reject Obama’s handling of the threat posed by the Islamic State in Iraq and Syria, where Obama has been escalating the U.S. military’s involvement in a bid to break a vexing stalemate. Support for his approach has followed a downward trajectory since the U.S. formed its coalition to fight the group in late 2014. Last September, Americans were roughly split, yet disapproval has jumped 8 percentage points just since January.

Those concerns mirror broader trepidation about Obama’s management of foreign policy, which garnered approval from just 40 percent of Americans in the AP-GfK poll. They come as Obama struggles to demonstrate progress advancing U.S. interests in the Middle East, where Obama hoped to disentangle the U.S. military after a decade-plus of war but will likely leave three military conflicts ongoing when his presidency ends in 2017.

Complicating Obama’s efforts to strike the right balance, his critics include both those who feel he’s betrayed his pledge to keep U.S. troops out of combat in Iraq and Syria and those who argue exactly the opposite: that Obama is pursuing half-measures that put U.S. troops at risk but are too paltry to make a decisive difference.

“ISIS is literally laughing at our president,” said Donald Hammond, a retired police officer and Republican from Brooklyn, Ohio. He accused Obama of tying the military’s hands out of concern about potential U.S. casualties. “If we’re going to be committed to the fight, he needs to commit seriously and stop playing patty-cake.”