Ukraine's ruling coalition fell apart following the withdrawal of the People's Front party in a move that casts doubts on President-elect Volodymyr Zelenskiy's plans to hold early parliamentary elections.

The remaining parties now have 30 days to form a new coalition.

Under Ukrainian law, the president cannot dissolve the Parliament — a requirement for calling early elections — without a governing coalition, The Associated Press reported.

Zelenskiy, who won last month against Petro Poroshenko, will be sworn in May 20. A comedian with no prior political experience, he vowed to tackle corruption, which he said is Ukraine's biggest problem.