Turkish President Recep Tayyip Erdogan has accused the United States of creating a "pool of blood" in the region by failing to recognise Kurdish organisations as terror groups.

Key points: Turkish President slams US policy on Kurds

Turkish President slams US policy on Kurds Asks whether the US is with terrorists or Turkey

Asks whether the US is with terrorists or Turkey Stance on Kurds complicates peace talks

"Hey America! ... As you have never recognised them (as terror groups) the region has turned into a pool of blood," Mr Erdogan said in a lacerating attack on US policy, referring to the Syrian Kurdish Democratic Union Party (PYD) and its People's Protection Units (YPG) militia.

In an impassioned and sometimes angry address, Mr Erdogan asked whether the United States was an ally or was working with groups Ankara lists as terror organisations.

"Hey America! How many times have we had to tell you?" Mr Erdogan said in his fiery address.

"Are you together with us or are you with the PYD and YPG terror groups?"

His remarks escalated a growing row between Washington and key NATO member Turkey over the role of Kurdish fighters in the struggle against jihadists in Syria.

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

Kurdish policy complicates Syria talks

Mr Erdogan launched the attack in one of his regular speeches at the presidential palace to loyal local municipal leaders known as muhtars that have become known as the forum for his most vehemently anti-Western comments.

"Is there a difference between the PKK and the PYD? Is there a difference with the YPG?" asked Mr Erdogan.

"We have written proof! We tell the Americans 'it's a terror group'. But the Americans stand up and say 'no we don't see them as terror groups'."

Turkey says the Syrian Kurdish groups are simply a branch of the rebel Kurdistan Workers Party (PKK), which is recognised as a terror group by the United States, and has carried out a string of deadly attacks in Turkey in the last months.

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

The growing row on the role of the Kurds risks further complicating the search for a solution to Syria's five-year conflict, drawing a wedge between two key members of the anti-IS coalition and driving another nail into the coffin of a process of peace talks.

In a further twist, a Syrian Kurdish group on Wednesday opened a representation in Moscow, which is currently in the throes of a diplomatic crisis with Ankara and is working to tighten ties with the Kurds.

AFP/Reuters