KYIV, March 12 – Ukraine will sue Gazprom to seize its assets around the world if the Russian company refuses to pay $2.56 billion penalty ordered by an arbitration court, President Petro Poroshenko said.

"Russia's statements that it will not pay Ukraine under the Stockholm arbitration ruling are a weak position,” Poroshenko said. “There is no use throwing punches after the fight is over.”

“There are international conventions and there is an impeccable legal position of Ukraine," Poroshenko said.