Turkish President Recep Tayyip Erdogan has told US President Donald Trump that his country will not accept Syrian Kurdish fighters in the region, but stopped short of criticising a US decision to arm them.
At a joint White House press conference, Mr Trump lauded Mr Erdogan as an important ally in the "fight against terrorism".
Mr Trump did not mention the Turkish president's domestic crackdown after last year's failed coup attempt.
"We've had a great relationship and we will make it even better," Mr Trump said in their joint appearance.
Mr 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 the US decision to arm the Syrian Kurdish YPG, or People's Protection Units.
US officials disclosed on 9 May Mr Trump's approval of plans to supply the YPG as it advances toward the so-called Islamic State's stronghold of Raqqa in Syria.
Mr Erdogan had pledged to use the White House meeting to try to get Mr Trump to change course on the YPG, which Ankara regards as an extension of the outlawed Kurdistan Workers Party, the PKK.
The PKK has fought an insurgency in south eastern Turkey since 1984 and is considered a terrorist group by the United States, Turkey and Europe.
The United States sees the YPG as distinct from the PKK and as a valuable partner in the fight against IS.
The administration of Mr Trump's predecessor, Barack Obama, had criticised Mr Erdogan's crackdown on the Turkish press and academia after the failed coup in July 2016.
Tens of thousands of Turkish citizens have since been detained and some Erdogan supporters sought to blame the United States for the coup attempt.
At their joint press conference, Mr Trump made no mention of Mr Erdogan's record on dissent and free speech.