Senate Democrats met with top Biden campaign officials behind closed doors Thursday for about two hours trying to lay out the path to victory for the president.

One senator said the meeting was 'tense' at times.

A number of senators expressed concerns about the president being shielded by his advisers, two sources with knowledge of the meeting told ABC News.

Some senators stated they were being put in "difficult," "impossible" or "untenable" positions by having to defend the president to constituents back home after the debate, especially for those senators in tough races, according to the sources.

No Biden campaign polling was shared with senators but instead Biden's advisers laid out a strategy, including showcasing the president's record, going after Trump, campaigning on a second-term agenda and building out the coalition of voters, sources said.

One senator who spoke to ABC News said, "I needed to see hard data that showed a path to success in November and we did not get that."

"I continue to have concerns that only Joe Biden can address, not his campaign staff," the senator said.

-ABC News' Rachel Scott and Allison Pecorin

Arizona Democratic Rep. Greg Stanton became the 13th House member to openly call on Biden to leave the race Thursday.

Stanton touted Biden's years of work in his statement but said the president's "most defining legacy, though, is as a fierce defender of American democracy.

"The Democratic Party must have a nominee who can effectively make the case against Trump, and have the confidence of the American people to handle the rigors of the hardest job on the planet for the next four years," Stanton said.

-ABC News' Lauren Peller

Democratic Rep. Ed Case of Hawaii became the latest House member to call on the president to cease his reelection run.

Case released a statement Thursday saying, "Difficult times and realities require difficult decisions."

"This has nothing to do with his character and record. If it did, there would be no decision to make," he said. "This is solely about the future, about the President’s ability to continue in the most difficult job in the world for another four-year term."

-ABC News' John Parkinson

A foreign pool reporter at the third working session at the NATO summit taking place in Washington asked French President Emmanuel Macron what his impression of Biden was.

"I don’t understand your question about President Biden. He is my counterpart, he is the President of the United States, and we are happy to have him as the president of the United States," Macron replied.

Macron spent ample time with Biden just a month ago during his visit to France.

-ABC News' Michelle Stoddart