NEW YORK (Reuters) - New York City Mayor Bill de Blasio on Friday ended his 2020 presidential campaign that was overshadowed by better-known liberal Democrats, and drew a sarcastic farewell from a fellow New Yorker, President Donald Trump.

“Sometimes it’s just not your time, and that’s OK,” de Blasio, 58, told reporters.

De Blasio launched his long-shot candidacy in May with the central slogan, “Working People First,” and found himself in a crowded field of Democrats hoping to take on the Republican Trump in next year’s election. De Blasio’s exit leaves 19 Democrats vying to be the party’s nominee.

The mayor, barred from seeking a third four-year term in New York in 2021, struggled to build a national profile and stand out in a field that included former Vice President Joe Biden and a long list of experienced politicians.

De Blasio had registered little support in polls and was eclipsed by progressive U.S. senators Bernie Sanders and Elizabeth Warren.

Trump greeted news of de Blasio ending his presidential bid with sarcasm.

“Oh no, really big political news, perhaps the biggest story in years! Part time Mayor of New York City, @BilldeBlasio, who was polling at a solid ZERO but had tremendous room for growth, has shocking dropped out of the Presidential race,” Trump, a New York real estate developer before running for president, wrote on Twitter. “NYC is devastated, he’s coming home!”

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De Blasio, who announced the move on MSNBC’s “Morning Joe” program, later gave a news conference outside the mayoral Gracie Mansion residence. He said the party’s rules for qualifying for televised debates had made it hard for him to continue. He failed to qualify for a Sept. 12 debate that featured the 10 leading candidates for the party’s nomination.

“We were watching the polling to see if anything was moving and it just wasn’t moving,” he said.

Democrats require candidates to reach certain levels in opinion polls and fundraising to qualify for the debates, which de Blasio said had become the “Main Street” of the campaign.

‘PROGRESSIVE ENERGY’

Biden and Warren both took to Twitter to praise de Blasio’s efforts on behalf of “working families.” In his news conference, de Blasio did not endorse a candidate but said “the electorate is going to push” Biden, who has staked out more centrist positions than some of his rivals, in a leftward direction as the campaign continues.

“There’s so much progressive energy in this party you’ve probably seen him go farther on climate and healthcare than he might have on his own,” the mayor said of Biden.

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De Blasio emphasized during the campaign a list of liberal wins under his leadership, including universal pre-kindergarten, the end of the policing practice known as stop-and-frisk and paid sick leave, all in a city that has a bigger population, more than 8 million, than most U.S. states.

Most New Yorkers had appeared unenthusiastic about de Blasio’s presidential aspirations. A Quinnipiac University poll in April found more than three-quarters of New Yorkers did not feel he should make a White House bid.

Mayor Pete Buttigieg of South Bend, Indiana, which has a population just over 100,000, won more support in national polls and regularly raises money at well-attended events in New York.

De Blasio’s challenges were on display at one of his final campaign appearances at a presidential forum on Monday in the town of Galivants Ferry in South Carolina. He spoke after U.S. Senator Amy Klobuchar, Buttigieg and Biden as the sun set, but by that point, more than half of the audience had left.