U.S. Senator Dianne Feinstein (D-CA) at the U.S. Capitol in Washington
U.S. Senator Dianne Feinstein (D-CA) moves through the Senate subway during a vote at the U.S. Capitol in Washington, U.S., September 21, 2022. Reuters

The standoff over raising the U.S. federal government's $31.4 trillion debt ceiling illustrates the stakes of U.S. Senator Dianne Feinstein's lengthy absence from Washington, fellow Democratic Senator Amy Klobuchar said on Sunday.

Feinstein, 89, faced calls from some fellow Democrats last week to resign her seat after being sidelined since early March by a bout of shingles. On Wednesday she said she would temporarily step down from her spot on the Judiciary Committee while she recovers.

"We are going to need her vote on the Senate floor eventually. We have things like the debt ceiling coming up," Klobuchar said in an interview on ABC's "This Week" program.

Congress has been locked in a standoff over the debt ceiling since January, with the Republicans who control the House of Representatives saying they will vote to raise it only in exchange for federal spending cuts. President Joe Biden's Democrats insist on a "clean" debt ceiling bill unaccompanied by cuts.

Democrats control the Senate by a narrow 51-49 margin, making every vote critical.

Feinstein said on Wednesday that she will continue to work from her San Francisco home, which will prevent her from voting in the Senate, where she has not cast a vote since mid-February.

"I intend to return as soon as possible once my medical team advises that it's safe for me to travel," Feinstein said.

Senate Majority Leader Schumer will ask the Senate this week to allow another Democratic senator to temporarily serve on the Judiciary Committee.

Klobuchar, a Senate Judiciary Committee member, said the trail-blazing California lawmaker had "made the right decision" to step aside until she is able to resume work, but the closely divided Senate could not cope with her absence indefinitely.

"If this goes on month after month after month, then she's going to have to make a decision with her family and her friends about what her future holds, because this isn't just about California. It's also about the nation," Klobuchar said.

Feinstein on Wednesday faced the first public calls for her resignation from fellow Democrats.

Representative Ro Khanna of California, who last week urged Feinstein to step down, said she was no longer able to do the job in an appearance on "Fox News Sunday."

"I have a lot of respect for Senator Feinstein, but she's missed 75% of votes this year. She hasn't been showing up," Khanna said. "She has no return date."

Also appearing on "Fox News Sunday," U.S. Senator Kirsten Gillibrand defended Feinstein, saying she should be allowed to make up her own mind when or whether she will retire before her term ends after the 2024 elections.

"It's her right. She's been voted by her state to be senator for six years. She has the right in my opinion to decide when she steps down," Gillibrand said. "Dianne will get better. She will come back to work."

A representative for Feinstein could not be immediately reached for comment.

Feinstein is one of three senators who recently have been out for medical reasons. Mitch McConnell, 81, the Senate's top Republican, was treated for a concussion after falling at a dinner in Washington. Democratic Senator John Fetterman was hospitalized for depression earlier this year while recuperating from a stroke.

McConnell and Fetterman are expected to return to work on Monday.