KIEV, Ukraine — Prime Minister Arseniy P. Yatsenyuk resigned abruptly on Thursday after the governing coalition of Parliament collapsed, creating uncertainty about the makeup of the government in Kiev as it continues its fight against pro-Russian separatists in the country’s restive east.

“I declare my resignation in connection with the collapse of the coalition and blocking of government initiatives,” Mr. Yatsenyuk said after two major parties announced they were pulling their support, a step that allows President Petro O. Poroshenko to dissolve Parliament and call elections for the fall.

The move to dissolve the coalition was not supported by Mr. Yatsenyuk’s Fatherland Party, and in his speech to Parliament, Mr. Yatsenyuk warned that the political maneuvering risked paralyzing the government.

“Our government now does not have an answer to the question how to pay salaries,” he said. “How to support the army and armed forces? How not to demoralize the spirits of those tens of thousands of people who are sitting not in this hall, but in trenches under bullets?”