B.C. Green Party Leader Andrew Weaver has announced he will be stepping down as party leader and will not run for re-election in the riding of Oak Bay-Gordon Head in the 2021 provincial election.

Weaver says he will stay on as party leader until a replacement is found.

"The decision not to run for re-election has not been easy for me," he said.

"I feel a deep responsibility and pride for the role the B.C. Greens have played in getting the province back on track to meet its climate commitments and to reframe climate change as an economic opportunity — instead of a purely environmental catastrophe."

The announcement does not immediately change the balance of power in the province, where the three-member Green Party caucus currently supports the minority NDP government through a confidence and supply agreement.

The NDP holds 41 seats, the Greens three and the Liberals 42 seats. Speaker of the House Darryl Plecas is an independent.

Watch: Andrew Weaver says he's proud of what his party has accomplished in his time as leader

Outgoing B.C. Green Party Leader Andrew Weaver says he spent the summer reflecting on whether to seek another term as an MLA for Oak Bay-Gordon Head. 2:34

Time for a 'new generation'

Weaver said he believes the B.C. Greens' next leader should reflect the largely youth-driven push for climate action.

"Their momentum is growing," he said. "It's time to let a new generation lead."

B.C. Green Party Leader Andrew Weaver and B.C. NDP Leader John Horgan take in the final match between Canada and New Zealand at the HSBC Canada Women's Sevens rugby tournament in Langford in 2017. (Chap Hipolito/The Canadian Press)

Premier John Horgan said he is disappointed that Weaver will be leaving the legislature.

"I wouldn't have expected 2½ years ago that Andrew and I would have become the friends that we have," said Horgan.

Weaver highlighted the CleanBC economic plan as the major achievement of his time in office. The strategy was introduced last December as a roadmap for stimulating economic activity aimed at reducing greenhouse gas emissions.

Watch: Members of the B.C. Legislature say they support Weaver's decision

B.C. Premier John Horgan says he wouldn't have expected to have formed such a good friendship with B.C. Green Party Leader Andrew Weaver. Members of the Green Party say they respect his decision and it will be business as usual at the legislature. 1:17

In an interview with CBC in December 2018, Weaver said he found his role of providing sober second thought and oversight to the government rewarding. He also hinted at the heavy workload involved in the position.

Weaver told the assembled media in Victoria on Monday morning that he'd been thinking about his future in politics since the summer, and denied that a recent health issue had anything to do with his decision.

On Sept. 16, Weaver tweeted that he had suddenly taken ill with labyrinthitis, an inner-ear disorder that can induce dizziness, nausea and loss of hearing.

Weaver said he has no intentions of running federally.

Under Weaver, the B.C. Green Party has made strides toward becoming a legitimate player on the B.C. political scene, also electing Adam Olsen in North Saanich and the Islands, and Sonia Furstenau in Cowichan Valley in the last provincial election.

Last year the party announced it had set a new record for individual donations, raising more than $710,000.