Germany's Greens voted in a party congress to support formal coalition talks with the Social Democrats and Liberals that could see the three parties form a government.
"We have the chance to take on responsibility and play a decisive role in this government of progress. We are happy to face this responsibility," the party tweeted on Sunday after the vote paved the way for formal negotiations to take place.
The Greens came in third place in the September 26 election with nearly 15% of the vote share, becoming potential kingmakers in a German coalition government.
The party agreed on Friday with the Social Democratic Party (SPD) and Free Democratic Party (FDP) to open coalition negotiations following exploratory talks. The pro-business FDP leadership is expected to approve formal talks as well on Monday.
The government would be under Social Democrat Olaf Scholz, the current vice-chancellor and finance minister, whose party finished first in the election.
Among the Green Party's priorities for a new government are extensive climate protection and strengthened social justice.
"Our focus is on the major tasks of the future and on saying: this decade is the one in which we will put Germany on the 1.5-degree path," the Greens' co-leader and chancellor candidate Annalena Baerbock said.
Party co-leader Robert Habeck said: "We are entering a new phase in green history in which we will have the chance to shape reality. We want responsibility. We want to shape reality."
The initial agreement between the parties includes accelerating Germany's phasing out of coal and investing more in renewable energy. But the partners said they would not raise taxes on the rich as the liberal Free Democrats were against such a measure.
Scholz has said he hoped a coalition government could be formed before Christmas.
It's uncertain whether formal talks will lead to a government, however, with the centre-right FDP needing to compromise with the more left-leaning SPD and Greens. The FDP previously walked away from coalition talks in 2017 that involved the Christian Democrats and Greens.
An SPD-Green-FDP government -- known as a traffic light coalition for the parties' colours -- would put Angela Merkel's Christian Democrats (CDU) into opposition for the first time in nearly 16 years.
Merkel had announced in 2018 that she would not run for chancellor in the 2021 election.
The CDU's chancellor candidate Armin Laschet took responsibility for the party's election loss on Saturday, calling for unity within the party.