The chief of Putin's presidential staff Sergei Ivanov, said the Kremlin was ready to respond to a Ukrainian lawsuit against Russia regarding the annexation of Crimea.

The statement comes days after Petro Poroshenko, who was declared the Ukrainian presidential election winner on Monday, told a press briefing that the solution of the Crimean problem was a primary objective. He noted that Ukraine would stand up for its right to Crimea at international courts.

Poroshenko received more than 53 percent of the vote, according to Ukraine's Central Election Commission. Former Prime Minister Yulia Tymoshenko trailed behind Poroshenko with about 13 percent.

European Union leaders praised Ukraine’s presidential election and vowed to support the country’s new leader as he assumes power in a country struggling with a flailing economy.

To recall, Russia annexed Crimean peninsula, following May 16 Crimean referendum. However neither Kyiv, nor international community recognized the annexation.