European Union governments ready to expand sanctions if the conflict in Ukraine intensifies

European Union governments warned Russian President Vladimir Putin that they’re ready to expand sanctions if the conflict in Ukraine intensifies.

Citing a “worsening crisis in eastern Ukraine and its humanitarian impact on the civilian population,” EU foreign ministers urged Russia in a joint statement to stop “any form of border hostilities,” including arming pro-Russian separatists, and to pull back its forces from the border.

Illustrating the stakes, Ukraine said its troops attacked an armed convoy that had crossed the border from Russia just as the 28 ministers wound up emergency talks in Brussels yesterday. While Russian officials denied that the incident occurred, U.S. and European stocks tumbled on the news.

British Prime Minister David Cameron’s office issued a statement saying he expressed “grave concern” at the reports during a call with Ukraine’s President Petro Poroshenko. The U.K. called in the Russian ambassador to explain the reports.

“Russia doesn’t seem to have changed its strategy and is continuing creating instability in eastern Ukraine,” Dutch Foreign Minister Frans Timmermans told reporters in Brussels. If Russia sent vehicles into Ukraine and they were attacked, it’s “further proof that Russia continues destabilizing the situation and that is not helpful, to say the least,” he said.