Poland's President Andrzej Duda is calling for U.N. peacekeepers to be sent to the Russia-Ukraine border and all territory controlled by separatists in eastern Ukraine.

Duda stressed "in the strongest terms" to reporters Thursday the importance of deploying a peacekeeping mission.

Russia-backed separatists and Ukrainian forces are engaged in a long-running conflict in the east which has killed more than 10,000 people. It was sparked by Russia's annexation of Crimea.

Last September, Russia proposed a draft Security Council resolution on sending U.N. peacekeepers to eastern Ukraine to provide security for monitors from the Organization for Security and Cooperation in Europe.

Days later, Ukrainian President Petro Poroshenko called for a U.N. peacekeeping mission with a mandate over the entire Ukraine-Russia border.

Both resolutions faced likely vetoes, and have been shelved.