WASHINGTON (Reuters) - The 1.3 million-member Teamsters union could decide who to endorse in the 2024 U.S. presidential election as early as Wednesday after members met Democratic candidate Kamala Harris on Monday, Teamsters President Sean O'Brien said.

Union representatives met her Republican rival Donald Trump in January. "We can't kick this can down the road," O'Brien told reporters after meeting with Harris for nearly an hour.

Most major unions have endorsed Harris, including the United Auto Workers union. The AFL-CIO, which represents 60 unions and 12.5 million workers, endorsed Harris in July. The Teamsters are one of the country's largest unions.

O'Brien spoke to the Republican National Convention in July but also criticized Trump for suggesting that workers who go on strike could be fired.

The union will present results of polling it did of its members to the executive board on Wednesday.

Asked if the union could opt not to make an endorsement, O'Brien said: "We are going to look at any and all options. ... We need to make sure we make the right decision."

The Teamsters endorsement could be a factor in a handful of battleground states that will decide the Nov. 5 election, including Michigan, Nevada and Pennsylvania where unions are strong.

He said the polling is significant but not the only factor the union will consider in making an endorsement.

The Harris campaign did not immediately comment.

O'Brien said they had discussed with Harris Amazon.com.

The union said earlier on Monday that hundreds of delivery drivers for Amazon ( AMZN ) across three Delivery Service Partners (DSP) in Queens, New York, are demanding Amazon ( AMZN ) recognize their union and negotiate a Teamsters contract, the union said.

O'Brien said they had talked about proposed legislation governing the ability of workers to join a union.

"There's no secret that the Teamsters union is very different than most unions," O'Brien said. "We don't just represent registered Democrats, we represent registered Republicans and independents. ... We have to take that into consideration."

The Teamsters, founded in 1903, endorsed Biden in 2020, as well as Democrats Hillary Clinton in 2016 and Barack Obama in 2008 and 2012, though they sometimes picked Republicans in earlier elections.