US President Barack Obama met his Turkish counterpart Recep Tayyip Erdogan in Washington Thursday, the White House said, amid serious tensions over press freedom and the global war on Syria.

US President Barack Obama met his Turkish counterpart Recep Tayyip Erdogan in Washington Thursday, the White House said, amid serious tensions over press freedom and the global war on Syria.

Having previously stated the pair were unlikely to hold sit-down talks - a decision widely perceived as a snub by Washington - the White House said the two men had in fact met on the margins of a nuclear security summit.

They discussed "US-Turkey cooperation on regional security, counterterrorism, and migration," it said.

The absence of a presidential meeting on Erdogan's trip to the US capital had been glaring, despite that the two countries are meant to be close NATO allies in the thick of a fight against the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group mainly operating in Iraq and Syria.

The White House has been increasingly outspoken in recent months about threats to free speech and democracy in Turkey.

And on Thursday it restated its belief in the need for press freedom in Turkey, amid ugly scenes at an Erdogan speech in the US capital.

The US National Press Club accused Erdogan of trying to export oppression.

According to the White House, Obama "extended condolences to President Erdogan on behalf of the American people for those killed and injured in the latest terrorist attack."