Is Trump-Erdogan's 'bromance' the only thing holding relations together?

Barely a month seems to go by before Turkey and the U.S. are thrown in to yet another diplomatic crisis.

But there's a simple reason why President Trump will still warmly welcome Turkey's leader Tayyip Erdogan at the White House on Wednesday....he likes him.

He's called him "a friend" and a "hell of a leader."

Since becoming the U.S. president, Trump has openly complimented Erdogan and his combative ruling style.

It's this fondness that's seen by many as the only reason why relations haven't completely collapsed.

The countries have major disagreements over a host of issues.

And there'll certainly be plenty of thorny issues for the pair to get stuck in to.

Just before he boarded the plane, Erdogan said he'd be telling Trump that the U.S had failed to keep its promises on Syria.

And had not removed the Syrian Kurdish YPG militia - America's allies in the fight against Islamic State - from along Turkey's border.

(SOUNDBITE) (Turkish) TURKISH PRESIDENT TAYYIP ERDOGAN SAYING:

"We will express (Mr. Trump) with documents that our agreement on this military operation has not been fulfilled."

Then there's Turkey's purchase of Russian missile defence systems.

The U.S. has been livid over it while Turkey has just shrugged off threats of U.S. sanctions.

Washington did remove Turkey from the F-35 fighter jet program - they were a manufacturer and buyer.

Getting Erodgan to drop his plans to use the S-400's and agree to a permanent ceasefire in Syria will be Washington's main goals of the meeting.

Some lawmakers tried to push Trump in to rescinding Erdogan's invitation at the last minute.

But after a warm telephone call between the two leaders just last week that 'bromance' still trumps major policy disagreements.