In Washington, Turkish Prime Minister Recep Tayyip Erdogan and US President Barack Obama held talks on trade, security and Syria. Turkey has been looking for stronger international action in Syria's civil war.
In a rainy press conference in the White House's Rose Garden Thursday, Obama reaffirmed to his NATO ally that the United States is committed to mutual security. He also expressed his condolences for last weekend's deadly bombings in the Turkish border town of Reyhanli.
On Syria, Obama said: "We're going to keep increasing the pressure on the Assad regime and working with the Syrian opposition."
The President added: "We both agree that Assad needs to go," with the transfer of power to a transitional body.
Obama praised what he called Turkey's "generosity" towards refugees from Syria. He said the US would keep helping to shoulder the burden of humanitarian aid.
Hundreds of thousands of Syrians have fled across the border to escape the fighting. Only half of them are living in refugee camps. The others have settled in towns and cities along the 900-kilometer (550-mile) border between Turkey and Syria.
According to the United Nations, the number of Syrian refugees in Turkey could climb to 1 million by the end of the year.
Obama, however, made no comment to establishing a no-fly zone in Syria - a proposal mooted in Turkey ahead of the premier's US visit.
Erdogan is under domestic pressure following last weekend's attacks in the Turkish border town of Reyhanli, which Ankara has blamed on terrorists with links to the Syrian regime.
There have been protest demonstrations in Reyhanli and other nearby towns since the bombings, with some blaming the security problems on Ankara's policy of supporting the Syrian opposition.
The two leaders also discussed expanding investment and trade, which has surged between the United States and Turkey in recent years, Obama said. He added that he was keen to make sure that this would continue, even as Turkey was not yet a member of the EU.
The talks came a day before Russian President Vladimir Putin, was to meet UN Secretary General Ban Ki-moon, and after UN members voted to condemn an "escalation" by Assad's forces.
jm/mkg (AP, AFP, Reuters)