He announced the move on WCVB-TV after Kraft and Wu bested two challengers to advance during a preliminary election Tuesday.

Despite spending millions of his own money on the race, Kraft struggled to find a message that would resonate with voters amid the popularity of Wu. She is Boston´s first female and Asian mayor and has been bolstered in part by her defense of the city against the Trump administration.

Kraft told supporters in a letter provided to The Associated Press that the election had never been about him or Wu.

“We could spend the next eight weeks politicking-with harmful rhetoric or nasty attack ads. Or we could get back to what really matters – the issues that impact Bostonians each and every day. The work I have focused on for my whole career,” Kraft wrote.

Kraft said the decision was the right move “during a time in America where we need to come closer together despite all our differences, instead of igniting divisiveness that pulls us further apart.”

He said he planned to support efforts to provide workforce training for former inmates as well as address concerns about homelessness and drug addiction in a section of the city known as Mass and Cass. He said the investment would total $3 million, a combination of funds he planned to dedicate to his campaign and additional dollars.

As of the end of August, Kraft had outspent Wu, $5.5 million to about $1.1 million, thanks in large part to more than $5 million in loans from the candidate to his campaign.

Wu won around 72% of the vote in Tuesday´s election, compared with Kraft´s 23%.

In an email statement Thursday night, Wu said she respects Kraft´s decision and thanked him “for caring about our city deeply enough to want to make it better.”

“We are going to continue over the next two months and beyond to keep engaging our community members about the critical work in front of us and how we keep making Boston a safe, welcoming home for everyone,” she said.

The week of the preliminary election, U.S. immigration began a new operation in Boston to follow a May surge that resulted in the arrest of nearly 1,500 arrests.

The Trump administration, often led by border czar Tom Homan, has been accusing Boston of not doing enough to crack down on illegal immigration. Boston is commonly known as a sanctuary city, and Wu has repeatedly said she wants it to be a welcoming place for immigrants.

Trump´s U.S. Department of Justice filed a lawsuit last week against Wu, the city of Boston and its police department over its sanctuary city policies, saying they´re interfering with immigration enforcement. In response, Wu accused Trump of “attacking cities to hide his administration´s failures.”

It was unclear whether another candidate would be eligible to replace Kraft on the Nov. 4 ballot.