Vice President Joe Biden, on a visit to Turkey, discussed the situation in Syria with President Abdullah Gul during a brief stop Friday in Ankara. A senior official who talked to reporters on a flight to Istanbul said Biden told Gul the United States believes Syrian President Bashar Assad is the major source of instability in the region. Biden said Turkey and the United States have a common goal, stopping the violence in Syria and convincing Assad to leave office. Biden praised Turkey\'s constitutional reform process. He said the country can set an example for others in the region following the events of the Arab Spring. In Istanbul, Biden is scheduled to attend the Global Entrepreneurship Summit Saturday and to meet with Prime Minister Recep Tayyip Erdogan. He travels to Greece Sunday, where he will meet Monday with President Karolos Papoulias and attend a lunch meeting with Prime Minister Lucas Papademo. Clinton said it was prudent for Suu Kyi to capitalize on signs of change in the country but said more reform is needed. \"There has to be a momentum behind reform and we\'re waiting and watching for that,\" Clinton said. Suu Kyi urged other countries to support Myanmar\'s march toward democracy. She also stressed the need to maintain friendly ties with China, her country\'s longstanding ally. Neither Clinton nor Suu Kyi brought up the U.S. sanctions against trade with Myanmar, and they are expected to remain in force for a while, The New York Times said. Clinton\'s visit was made possible after U.S. President Barack Obama, noting the recent changes in Myanmar, urged her to seek ways to widen relations. Clinton met with Thein Sein and other top government officials Thursday. She promised U.S. support to help in Myanmar\'s development, conditioned on the new government continuing with its reforms toward democracy. The two countries could even exchange ambassadors. CNN, quoting a State Department official, reported Clinton invited Myanmar\'s foreign minister to visit Washington and that he had accepted, but no date was set.