U.S. President Barack Obama said Russia must make a strategic decision about Syria and the next several weeks will show whether Russian President Vladimir Putin will give up backing the Syrian regime of Bashar Assad to join in a broad campaign against Islamic State.

The U.S. won¡¯t in any circumstances agree to a political settlement for the civil war in Syria that leaves Assad in power because he¡¯s lost all legitimacy, Obama said. As long as Assad remains, there is no way to unite the country¡¯s various factions for the fight against Islamic State.

¡°It is not conceivable that Mr. Assad can regain legitimacy in a country in which a large majority of that country despises Assad, and will not stop fighting so long as he¡¯s in power,¡± Obama said Sunday at a news conference in Kuala Lumpur.