By Sean Carney

PRAGUE--Czech leaders Monday waffled on supporting tougher sanctions against Russia following the Malaysia Airlines crash, potentially dealing a setback to the European Union as it seeks to increase pressure on Moscow.

Premier Bohuslav Sobotka said "without Russian military help, without Russian weapons, without Russian instructors, the separatists couldn't work at this level and it wouldn't have come to the tragic conflict in the eastern part of Ukraine."

Mr. Sobotka said his government supports calls for Russia to stop supplying weapons to separatists.

"Without a doubt Russia should unambiguously exert pressure on separatists" who enjoy Moscow's military and political support, he said.

However, on the topic of sanctions, he deferred to higher ups.

"If it comes to moving beyond the second phase of sanctions...to a third phase of sanctions, then the European Council will definitely have to decide, meaning on the level of heads of European states," said Mr. Sobotka.

Mr. Sobotka's remarks come just one day ahead of a summit of the EU's foreign ministers Tuesday in Brussels to coordinate the bloc's position toward Russia. If Mr. Sobotka defers to the head of state, President Milos Zeman, the outlook for a tougher line on Russia could be bleak.

Mr. Zeman earlier Monday said "sanctions have never been convincing."

"Every sanction, each embargo only results in you closing the given country into 'non-splendid isolation'," Mr. Zeman said.

"I rather believe what the Communists called ideological diversity, meaning the most frequent exchange of tourists, businessmen and students and a change of the system from within by democratic and legal means," he said.

Mr. Zeman described what is taking place in eastern Ukraine as civil war, rather than a conflict fueled to a large extent by neighboring Russia and in his statements he made no mention of suspected Russian involvement in supplying arms, mercenaries or support to militants.

Facts on who shot down the airliner point to separatists "rather than the Ukrainian or Russian government," Mr. Zeman said.

The Czech waffling comes as neighboring Slovakia Monday morning took a harder line against Russia, signaling a shift in the country's relatively balanced approach between the EU and Moscow.

Write to Sean Carney at sean.carney@wsj.com

(END) Dow Jones Newswires

July 21, 2014 14:48 ET (18:48 GMT)

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