The European Union will continue to work with Russia and Ukraine to reduce tensions between the two countries but will keep sanctions as an option, the EU's foreign policy chief has said.

At an informal meeting of EU foreign ministers in Athens, Baroness Catherine Ashton stressed the "need to persuade Russia to de-escalate the situation". Russia annexed the Crimean Peninsula last month following a referendum called just two weeks after Russian forces had overtaken the Ukrainian region. Ukraine and the West have rejected the vote and the annexation.