‍KIEV, Nov. 28 (CGTN) -- Ukraine President Petro Poroshenko accused Russian President Vladimir Putin of seeking to annex his entire country on Thursday, and warned that Ukraine's conflict with Russia could quickly spiral into a full-scale confrontation.

The Ukrainian Foreign Ministry has sent a note to Russia urging it to release the Ukrainian sailors who were detained during the confrontation in the Sea of Azov. Poroshenko asked NATO members including Germany on Thursday to send naval vessels to the Sea of Azov to back his country in the standoff with Russia.

On Wednesday, Putin accused the Ukrainian president of orchestrating the crisis to make the situation more tense.

The sea-clash cast a shadow over the planned meeting between the U.S. and Russia presidents in the upcoming G20 summit in Argentina. The between U.S. President Donald Trump and his Russian counterpart may be canceled after this confrontation. Donald Trump said on Tuesday, however, that he was still awaiting a “full report” from his national security team about the incident.

Putin said he still hoped to meet Trump at the G20, while the Kremlin said the meeting was still being prepared and Washington had not informed Moscow it was off.

The European Union (EU) will next month consider further sanctions against Russia over the latest flare-up in the Ukraine conflict, the foreign minister of Austria, which holds the rotating EU presidency, said Tuesday.

Some of Ukraine's Western allies have also raised the possibility of imposing new sanctions on Russia over the episode, which could deliver a blow to the Russian economy.