Ukraine's parliament is set to try to vote in a replacement for Prime Minister Arseniy Yatsenyuk amid a growing sense of political crisis.
On Sunday, Yatsenyuk announced that he would resign and accused Ukraine's politicians of failing to enact "real changes", BBC reported on Tuesday.
His government has been accused of inaction and corruption.
Parliamentary Speaker Volodymyr Groysman has been nominated by President Petro Poroshenko's party to replace Yatsenyuk.
However, reports late Monday suggested he may not take the post.
Economy Minister Aivaras Abromavicius resigned more than two months ago after accusing the government of not being committed enough to end corruption.
Yatsenyuk has been in office since former pro-Russian president Viktor Yanukovych was ousted during huge demonstrations in February 2014.
This latest crisis comes as the International Monetary Fund (IMF) has threatened to withhold aid money if Ukraine does not carry out reforms.