BRATISLAVA, Slovakia (AP) — Slovak Prime Minister Robert Fico has called a meeting the three parties in his ruling coalition after a junior partner, the ultra-nationalist Slovak National Party, unexpectedly announced it is withdrawing from the pact that brought the parties together.

Fico, who called the move "absurd," will meet leaders of the other two parties on Tuesday. He says he expects Slovak National Party chairman Andrej Danko to explain the reasons for the step.

It is not immediately clear whether the move threatens the government's existence. The coalition is made up of Fico's leftist Smer-Social Democracy party, the Slovak National Party and a party of ethnic Hungarians. It was created after last year's parliamentary elections.

The Slovak National Party said it wanted to negotiate new rules for the coalition, but didn't give details.