RANCHO MIRAGE, Calif — President Obama vowed Saturday to "fulfill my constitutional responsibilities" to nominate a successor to Justice Antonin Scalia on the Supreme Court and challenged Congress to grant his choice a fair confirmation hearing.

The president praised Scalia, who died of natural causes at 79 on Saturday, as "one of the towering legal figures of our time" who had "influenced a generation." Obama did not specify a timetable for his selection, and he did not take questions from reporters at an impromptu news conference here at the Omni Hotel. White House aides offered no further details.

Obama, who already has named two female justices to the nine-member court, has the opportunity to leave a broad mark on the nation's highest judicial panel. But Senate Majority Leader Mitch McConnell (R-Ky.) has vowed to block any nomination in an election year, saying that the next president should have the chance to make the selection.

The issue already has become embroiled in the 2016 campaign, with candidates in both the Republican and Democratic races weighing on Saturday.

Obama's remarks came after the White House scrambled to arrange an unscheduled statement from the president, who had been playing golf at the Stadium Course at PGA West in La Quinta. Obama is here for several days of leisure ahead of a two-day summit with Southeast Asian leaders starting Monday at the Sunnylands retreat in Rancho Mirage.