Ukraine under international law could declare invalid those agreements, which have been signed with Russia under the economic pressure, ex-foreign minister of Ukraine Volodymyr Ohryzko said.

"Any arrangements, which are foreseen by the agreements, are considered to be commitments. But if they have been signed under definite economic pressure, international law permits the country that was the object of the pressure to declare the invalidity of such deals," he said at the press conference in Kyiv talking on the results of the president's visit to Moscow.

He said that this is a well-known international law, which Ukraine has had to use before.