Speaker Emerita Nancy Pelosi spoke with President Joe Biden a week ago, telling the president that she and other members of the Democratic Party are concerned about him staying in the race, a source confirms to ABC News.

Pelosi told the president that the calls for him to step down from the ticket would grow, sources said.

It is possible that Pelosi could suggest Biden should step down publicly, a source said.

The news about Pelosi’s behind-the-scenes moves comes as associate Rep. Adam Schiff, who is running for Senate, spoke out publicly earlier Wednesday, saying Biden should “pass the torch.”

The president tested positive for COVID-19 Wednesday afternoon, the White House said.

Biden is experiencing "mild symptoms," White House press secretary Karine Jean-Pierre said in a statement.

Biden was campaigning in Las Vegas and attended one event earlier in the day, according to Jean-Pierre.

"He will be returning to Delaware where he will self-isolate and will continue to carry out all of his duties fully during that time," she said.

The White House doctor provided more details, stating Biden had a runny nose, "and non-productive cough, with general malaise." The president's temperature was 97.8 degrees and he had taken his first dose of Paxlovid, the doctor said.

-ABC News' Justin Fishel

Minnesota Gov. Tim Walz, the co-chair of the DNC Rules Committee, called Biden campaign chair Jen O'Malley Dillon on Tuesday to push for the delay of the virtual roll call that would officially nominate Biden, two people with direct knowledge of the call told ABC News.

Walz co-wrote the letter sent this morning to rules committee members, which set the proposal for an early August virtual nomination of Biden. The roll call could previously have been held as early as Sunday.

Walz told O'Malley Dillon that he has been hearing from other governors who want the roll call to be pushed back. The Biden campaign made the concession to push it back, one source said, and even helped to propose the solution.

Walz's efforts were separate from those of House Minority Leader Jeffries and Senate Majority Leader Schumer, the source said.

-ABC News' Isabella Murray

Senate Majority Leader Chuck Schumer and House Minority Leader Hakeem Jeffries pushed the party to delay its nominating process, multiple sources tell ABC News.

This comes after Schumer met privately with President Biden on Saturday in Rehoboth, Delaware. Following the meeting, Schumer only described it as a "good meeting."

This is the biggest indication so far that Schumer is keeping an open mind about Biden's future.

Schumer and Jeffries spoke and both agreed to make the push, according to the sources.

-ABC News' Rachel Scott and Allison Pecorin