Turkey's foreign minister, Mevlut Cavusoglu, will attend the US sponsored anti-ISIL meeting on March 22 in Washington. 

His visit comes at a time of deteriorating relations between Turkey and the US over Washington's support of Kurdish fighters in northern Syria. 

Earlier, Turkey has vowed to capture the Syrian town of Manbij if the US doesn’t clear out the Kurdish fighters who control it. 

Meanwhile, Ankara has repeatedly told Washington to stop supporting the Kurdish Democratic Union Party, or PYD, and its armed wing the YPG, in northern Syria.

According to the Turkish government, the YPG are simply an extension of the country's own Kurdish separatist militants, the PKK, deemed a terrorist organization by both Ankara and Washington. 

More than 40,000 people have been killed in over three decades of fighting between the Turkish state and the PKK.

The Turkish foreign minister says he sees no risk of a "faceoff" with US troops in Manbij, and Ankara is clearly signaling its impatience with Washington's backing of the Kurdish militia there.

Kurdish fighters in Manbij say they will defend any move by Turkey to take over the area, but it is unclear what role the US would then play, since Washington sees the Syrian-Kurdish militia as an effective fighting force against ISIL on the ground and therefore has been supporting them militarily.