President Obama has directed his staff to start selecting a replacement for the late Supreme Court Justice Antonin Scalia, the White House said Monday.

But there won't be a announcement on the nominee before the Senate returns Feb. 22, presidential spokesman Eric Schultz said during a press conference in Rancho Mirage, where the president is convening a summit of South Asian leaders this week.

Once Obama nominates a justice, after a vetting process likely to take at least several weeks, he'll run up against Senate Republicans, who have vowed they won't consider any pick by a lame-duck Democratic president in the hopes that one of their own can fill Scalia's spot next year.

Schultz also brushed aside Republicans' refusal to consider an Obama nominee as "a lot of bluster," according to a CNN report.

"This is not the first time that Republicans have come out with a lot of bluster, only to have reality ultimately sink in," Schultz said.

He pointed to a string of Obama victories over the GOP-led Congress that Republicans first said they flat-out opposed, including raising the debt limit, implementing the Iran nuclear deal and reauthorizing the Export-Import Bank.

"Republicans fell back when their positions aren't tenable," he said.

He also said the president expects the Senate to fulfill its constitutional responsibility and act on the nomination.

"There are no caveats. The Constitution does not include exemptions for election years or for the president's last term in office," he said. "There's no exemption for when a vacancy could tip the balance of the court."

The White House hasn't yet given a specific timeline for when it might name a nominee to replace Scalia, who was found deceased at a Texas resort ranch on Saturday.

But Schultz made it clear that the nomination wouldn't come while the Senate is in recess this week.

"The president will take the time and rigor this process deserves before selecting a nominee. I would not anticipate an announcement this week, especially given that the Senate is out of recess," Schultz said Monday.

"But as soon as the Senate returns, the president was very clear that he's going to fulfill his constitutional responsibility to nominate a successor to Justice Scalia."