WASHINGTON: Turkish President Tayyip Erdogan touted "outstanding" relations with the United States on Tuesday but emphasised Turkey will not accept Syrian Kurdish fighters in the region while stopping short of directly criticising a US decision to arm them.

Erdogan met at the White House with President Donald Trump, and both called relations between the two NATO allies strong.

"We've had a great relationship and we will make it even better," Trump said in a joint appearance with Erdogan.

Turkish President Tayyip Erdogan, accompanied by his wife Emine Erdogan, disembarks from a plane upon his arrival in Washington, US, May 15, 2017. Kayhan Ozer/Presidential Palace/Handout via REUTERS

Erdogan said his visit would "mark a historical turn of tide" and hailed "outstanding relations" between the nations. It was an especially positive tone considering the tensions over Washington's decision to arm the Syrian Kurdish YPG militia that Ankara regards as an extension of the outlawed Kurdistan Workers Party (PKK).

"There is no place for the terrorist organisations in the future of our region," said Erdogan, speaking through a translator. He added that the activities of the YPG and its political arm in the region, the PYD, "will never be accepted".

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US officials on May 9 disclosed Trump's approval of plans to supply the YPG as it advances toward the Daesh stronghold of Raqqa in Syria.

Turkey has been a crucial partner in the US-led coalition against Daesh forces. The US alliance with Turkey has proven pivotal in the battle against Daesh in Syria, providing the coalition with access to Turkey's Incirlik air base to wage strikes against the militants.

Erdogan had pledged to use the White House meeting to try to get Trump to change course on the YPG. Ankara regards the YPG as an extension of the PKK, which has fought an insurgency in southeastern Turkey since 1984 and is considered a terrorist group by the United States, Turkey, and Europe.

The YPG, or People's Protection Units, effectively serves as the military of the autonomous Kurdish-led regions that emerged in northern Syria with the retreat of state authority in 2011 that accompanied the outbreak of civil war.

The United States sees the YPG as distinct from the PKK and as a valuable partner in the fight against Daesh.

'Unbeatable'

Trump and Erdogan both emphasised the positive. "The relationship that we have together will be unbeatable," Trump said.

The meeting came amid an uproar in Washington over reports that Trump disclosed sensitive information regarding Daesh to senior Russian officials during a White House meeting last week.

Turkey's President Recep Tayyip Erdogan (L) shakes hands with US President Donald Trump as they give statements to reporters in the Roosevelt Room of the White House in Washington, US, May 16, 2017. REUTERS/Kevin Lamarque

Trump, who took office in January, has sought to reach out to Erdogan and was criticised by some in the United States for congratulating the Turkish president on his contested win in a referendum on constitutional changes that gave him sweeping new powers.

The visit was further complicated by Turkey's calls for the United States to take steps to extradite Turkish cleric Fethullah Gulen. Erdogan blames Gulen supporters for a failed coup attempt last July and has conducted a crackdown on them, drawing criticism from Washington. Gulen has denied involvement in the coup and remains in the United States.

The Turkish government has also raised concerns about a US criminal case against Reza Zarrab, a dual Turkish-Iranian national arrested last year and charged with helping Iran process millions of dollar in transactions that violated US sanctions against Tehran.