The announcement from Sanders’ top staffer represents the most stark signal yet that the progressive icon is considering ending his presidential campaign after losing the most recent round of nominating contests in Arizona, Florida and Illinois to his Democratic rival, former Vice President Joe Biden.

Another potential indicator of the senator’s campaign is its advertising activity. Sanders on Tuesday launched digital fundraising ads on Facebook, and they have all been pulled. He also has no active ads up on Facebook today, according to Advertising Analytics.

Previous failed White House hopefuls have issued similarly solemn remarks before inevitably dropping out of the 2020 race, including Massachusetts Sen. Elizabeth Warren, whose campaign manager said earlier this month that she would be “talking to the team to assess the path forward.” Warren exited the primary fight the next day.

An hour after Shakir released his statement, President Donald Trump again weighed in on the battle to challenge him in November’s general election, predicting that Sanders would concede the nomination to Biden in short order. Trump has long sought to stoke discord among Democrats during the primary campaign, apparently eager to reopen old party wounds from 2016.

“The DNC will have gotten their fondest wish and defeated Bernie Sanders, far ahead of schedule. Now they are doing everything possible to be nice to him in order to keep his supporters,” the president wrote on Twitter. “Bernie has given up, just like he did last time. He will be dropping out soon! MAGA/KAG.”

Sanders, who was once the primary’s undisputed frontrunner following impressive performances in Iowa, New Hampshire and Nevada, was quickly outflanked by Biden after the former vice president’s dominant showing in South Carolina and swift endorsements from former Democratic candidates.

Biden’s standing has only improved since then, as he continued to notch victories in the Super Tuesday primaries, as well as in several nominating contests over the past two weeks. The coronavirus pandemic has also frozen the dynamics of the race and usurped news coverage of the campaign, blunting Sanders’ efforts to achieve a late boost of momentum.

Still, Sanders’ imminent withdrawal from the 2020 field is far from assured, given his desire to propel the progressive movement and shift the Democratic Party’s platform further left at the presidential nominating convention this summer.