The U.S. is rejecting Turkish President Recep Tayyip Erdogan's call for a no-fly zone in northern Syria after its military helped push the Islamic State from the crucial border area.

"We have determined that a no-fly zone would not be the best dedication of U.S. resources," Ben Rhodes, White House deputy national security adviser, told reporters in Laos Tuesday.

Instead, he said, the U.S. wants to dedicate its military resources to "go after" the Islamic State and al Qaeda in Syria.

"We do not think a no-fly zone would resolve the fundamental issues on the ground … a no-fly zone would necessarily only be contained to one specific area, and we have problems with violence across the country," he said.

Rhodes gave Turkey credit for progress in clearing the Islamic State from along the Turkish border, "something we've been focused on for a long time," he said.

If Turkey can help maintain greater security in the area, it will help prevent the flow of foreign fighters in and out of Syria, a key priority for Washington and Ankara.

During a G-20 meeting in China over the weekend, Erdogan said he asked President Obama and Russian President Vladimir Putin to help establish a no-fly zone in northern Syria to help prevent Islamic State from returning to the area.

"This is my proposal to Mr. Putin and Mr. Obama," Erdogan told reporters, according to Agence France-Presse. "This can be done with coalition forces."

Turkey, which is hosting more than 2.5 million Syrians who fled the war-torn country, wants to stanch that flow and avoid foreign fighters from using its border to travel into the country and launch attacks or travel to Europe and the U.S. to plot attacks.

Months ago, Hillary Clinton backed a no-fly zone in Syria, but her more recent position on the topic is unclear.

"I do still support a no-fly zone because I think we need to put in safe havens for those poor Syrians who are fleeing both Assad and ISIS and so they have some place they can be safe," she said during a Democratic debate with Bernie Sanders in April.

The Obama administration has said Clinton's plans for a no-fly zone wouldn't work because Islamic State doesn't have planes and continues to massacre people on the ground over a large swath of territory.