BERLIN (Reuters) - U.S. President Barack Obama on Thursday said it would be naive to expect a 180-degree turn by Russia or Syrian President Bashar al Assad, but the United States and its allies would continue to try to affect change to end the deadly Syrian crisis.

Obama spoke at a joint news conference after a meeting with German Chancellor Angela Merkel.

(Reporting by Madeline Chambers and Paul Carrel; Writing by Andrea Shalal; Editing by Caroline Copley)