During the 2020 Czech regional elections, Kulhánek was elected as a member of the ČSSD in the Central Bohemian Region, where he received 136 preferential votes.[7]
Minister of Foreign Affairs of the Czech Republic
In April 2021, after Lubomír Zaorálek rejected his candidacy as Minister of Foreign Affairs of the Czech Republic, ČSSD requested Kulhánek to hold the position in the Second Cabinet of Andrej Babiš.[8] On 15 April, following a meeting with President Miloš Zeman at Lány Castle, Zeman appointed Kulhánek as foreign minister on 21 April.[9]
On 14 May 2021, in response to the 2021 Israel–Palestine crisis, Kulhánek decided to display the Israeli flag at Czernin Palace as a sign of solidarity with Israel, declaring that "Israel is facing an absolutely outrageous and barbaric attack".[10]
Czech ambassador to the United Nations
On 15 February 2022, Kulhánek was appointed Permanent Representative of the Czech Republic to the United Nations,[11] an occupation he hinted during his tenure as foreign minister in the second cabinet of Andrej Babiš.[12]
In 2023, Kulhánek resigned from ČSSD after disagreement with the party leadership course represented by Michal Šmarda.[13]