Turkish President Recep Tayyip Erdogan bitterly attacked ally the United States over its support for Syrian Kurdish groups.

Turkish President Recep Tayyip Erdogan bitterly attacked ally the United States over its support for Syrian Kurdish groups.

In an impassioned and sometimes angry address, Erdogan accused Washington of creating a "sea of blood" in the region by working with Kurdish groups Ankara lists as terror organizations.

The US has been supporting Syrian Kurdish Democratic Union Party (PYD) and its People's Protection Units (YPG) militia in their fight against Takfiri insurgents in Syria, but Turkey considers them to be terror groups allied to Kurdish rebels on its soil.

"Hey America! How many times have we had to tell you?" Erdogan said. "Are you together with us or are you with the PYD and YPG terror groups?"

"As you have never recognized them (as terror groups) the region has turned into a pool of blood."

His remarks escalated a row between Washington and Ankara over the role of Kurdish fighters in the fight against the Takfiri group, ISIL (so-called Islamic State in Iraq and Levant), in Syria.

"Is there a difference between the PKK and the PYD? Is there a difference with the YPG?" growled Erdogan. "We have written proof!"

"Allies don't tell each other my enemy's enemy is my friend. You must have principles. But there are no principles here."

Turkey on Tuesday summoned the US envoy to Ankara in protest after the US State Department said Washington did not recognize the PYD as a terror group and would continue to support its operations in Syria.

Ankara has also expressed outrage over a visit last week by US presidential envoy Brett McGurk to the Syrian Kurdish town of Kobane where he met YPG fighters.

"Even the best of friends aren't going to agree on everything," State Department spokesman John Kirby said earlier this week.

"Kurdish fighters have been some of the most successful in going after Daesh (Arabic acronym for ISIL) inside Syria."