"Hey America... As you have never recognized them (as terror groups) the region has turned into a pool of blood," 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.
His remarks escalated a growing row between Washington and key NATO member Turkey over the role of Kurdish fighters in the struggle against militants in Syria.
Turkey on Tuesday summoned the US envoy to Ankara in protest after the US State Department spokesman said that Washington did not recognize the PYD as a terror group and would continue to support its operations in Syria.
"Hey America! How many times have we had to tell you?" Erdogan said in his fiery address. "Are you together with us or are you with the PYD and YPG terror groups?"
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, AFP reported.
Turkey says that the Syrian Kurdish groups are simply a branch of the rebel Kurdistan Workers Party (PKK), which is recognized as a terror group by the United States, and has carried out a string of deadly attacks in Turkey in the last months.
"Is there a difference between the PKK and the PYD? Is there a difference with the YPG?" asked 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'."