Ukraine's Prime Minister Arseniy Yatsenyuk has urged countries not to lift sanctions against Russia until Ukraine regains control over its entire territory, including Crimea.
Yatsenyuk on Wednesday night told the annual U.N. General Assembly of world leaders that "we know what terrorism means."
He demanded that Russia pull back its forces from eastern Ukraine, "stop the supply of Russian-led terrorists" and start "real talks, peace talks."
The months-long fighting between pro-Russian separatists and Ukrainian forces has been a major theme of speeches at the global assembly this week.
Neither Russian President Vladimir Putin nor recently elected Ukrainian President Petro Poroshenko is attending the U.N. assembly.
The Security Council has met repeatedly on the crisis but failed to take action because Russia holds veto power as a permanent council member.