White House officials plan to conduct “robust engagement” with Congress throughout the entire process of nominating a Supreme Court justice to fill the seat of Antonin Scalia, according to White House spokesman Eric Schultz.

President Barack Obama wanted to take time after Scalia’s death and go through the nomination process in “a thoughtful and rigorous way,” Schultz told reporters at a news conference Monday in California. “So I expect that when the Senate returns within due time, the president will identify and announce a nominee.”

Schultz declined to further sharpen the timeline for announcing a pick or elaborate about potential nominees. Since the news Saturday of Scalia’s death, the White House has heard from lawmakers who reached out to the president, Schultz said.

“White House officials have been engaged with congressional offices, primarily on the Senate side, but both Democrat and Republican offices,” Schultz told reporters.  “Those conversations have been preliminary in nature but are a signal that we plan on conducting robust engagement throughout this entire process.”

“And then we’re also proactively reaching out to key offices,” Schultz said. “I don’t have a list here to detail. But I think in the coming days, that engagement and that outreach will become more extensive.”

Senate Republicans, including Majority Leader Mitch McConnell of Kentucky and Senate Judiciary Chairman Charles E. Grassley of Iowa, have said the appointment of a new justice shouldn’t come until after the presidential election in November.

Obama is already “deeply engaged” with the process, Schultz said, “working with his team, both White House officials who are back at the White House and back here, to make sure that this process is moving forward.”

Schultz also said it would be “irresponsible and unprecedented” to let a vacancy on the court extend into 2017.

“If Congress fails to act, the Supreme Court will preside for well over a year with a vacancy, and would not only impact two consecutive Supreme Court terms, it would be wholly unprecedented for the modern Supreme Court,” Schultz said. “In fact, since the 1980s, there’s never been any vacancy spanning more than one term.”