"We both agree that Assad needs to go," the president said. "He needs to transfer to a transitional body. That is the only way that we are going to resolve this crisis. We are going to keep working for a Syria that is free from Assad's tyranny, that is intact and inclusive of all ethnic and religious groups and that is the source of stability not extremism, because it is in the profound interests of all our nations, especially Turkey."
Prime Minister Erdogan said Turkish and U.S. views "overlap" on Syria, pointing to "full agreement" on the need to end bloodshed and establish a new government, describing key objectives as the departure of Assad, preventing Syria from becoming a base for terrorists, and preventing use of chemical weapons.
Related video report by Kent Klein
Erdogan then fielded a question about what impact there would be on the Syrian civil war if the U.S. does not step up its involvement.
"You are talking about the part of the glass which is empty," he said. "I would like to look at things with the glass half full, instead of half empty. What we would like to see is the sensitivity on the part of the international community with respect to what is going on in Syria. This is what we as Turkey strive for and I do believe the United States is doing the same."
When asked if he had presented evidence of chemical weapons use in Syria, he said information has been shared with all countries and the United Nations.
President Obama had this response when asked about his "red line" on the use of chemical weapons.
"The use of chemical weapons is something that the civilized world has recognized should be out of bounds," Obama said. "As we gather more evidence and work together, my intention is to make sure that we are presenting everything that we know to the international community as an additional reason and an additional mechanism for the international community to put all the pressure they can on the Assad regime."
Obama said he preserves the option to take additional steps, both diplomatic and military, saying chemical weapons threaten U.S. security and that of its allies and friends.
Thursday's Obama-Erdogan meeting also covered Turkish-Israeli talks to normalize their relations. Erdogan said he plans to visit Gaza and the West Bank in June, describing his upcoming trip as something that will help Palestinian unity.
On the topic of Israel-Palestinian peace efforts, and Iran, Obama said both world leaders agreed it is critical that Iran not be allowed to acquire a nuclear weapon and potentially trigger a regional arms race.