A possible conference of representatives of the Syrian government and opposition to attempt to end the civil war may be pushed back to early June, the State Department said Monday. State Department spokeswoman Jen Psaki noted that Secretary of State John Kerry said last week that the conference could be held by the end of May. "The secretary said at the time that he would like to do this as early as is practicable, and he said by the end of May, or ideally by the end of May, possibly," Psaki told reporters. "There are many different players, many different countries involved here. It looks like it will slip past that to possibly early June. I don't have an exact date at this point." "He (Kerry) has been in constant contact over the past couple of days, through the course of the weekend, since this announcement last week with the Russians, with stakeholders in the region, with leaders in the region. He's spoken with everybody from Special Envoy Al-Brahimi; he spoke with Foreign Minister Davutoglu both Friday and again this morning; He's spoken with Prime Minister Cameron," Psaki said. The spokeswoman said that Kerry is "looking forward" to holding the conference as soon as possible.