Ukraine's foreign minister welcomed US and European sanctions on Russia announced on Tuesday and pledged Kiev would not attack cities now controlled by pro-Russian separatists in its drive to re-establish control over its territory.

Pavlo Klimkin, in an interview with Reuters, supported the convening of a new international conference to end months of violence in eastern Ukraine and said he had discussed the idea with U.S. Secretary of State John Kerry earlier in the day.

Speaking at Ukraine's Washington embassy, he said ultimately only a political solution would end the conflict, in which pro-Russian forces hold a large swathe of territory near the border, including the cities of Donetsk and Luhansk.

"We will not attack such cities," he said, because it would trigger human losses. The Ukrainian authorities, he said, would regain control of the cities "through the political process, not by attacking those cities".

Intense fighting on Tuesday between Ukrainian government forces and rebels killed dozens of civilians, soldiers and rebels as Kiev pressed on with its offensive to defeat the Moscow-backed revolt.

Shells hit the center of Donetsk, a city with a pre-war population of nearly a million. Residents fear they will be trapped between the fighting forces after Ukrainian troops pushed rebel units back toward the city.

Klimkin, who had two days of talks in Washington, including a meeting with Vice President Joe Biden, said he was returning to Kiev on Tuesday night "with a clear message that both the U.S. and the EU simply speak with one voice supporting Ukraine."

He said it would have been "practically unimaginable" three or four months ago that the European Union would have agreed sectoral sanctions on its major trading partner Russia.

"The key point for me here is commitment to Ukraine, commitment to a united, democratic and European Ukraine."

POLITICAL STEPS

Asked about political steps Ukraine could make, he said: "We are ready to give far more freedom but also far more responsibility (to the regions), political, economic power to communities. But it is up to Russia now to influence the terrorists." Kiev refers to the separatists as terrorists.

"It is up to Russia to take back the key leaders of the terrorists, who are all Russian citizens and have a clear connection with the Russian security services," he said.

Reporting by Reuters earlier this month established that the most prominent leaders of the separatist groups are Russian citizens.

Ukraine finalised an association agreement with the European Union last month, but Klimkin played down any suggestion that Kiev would eventually seek to join NATO, a move viewed as unacceptable by Russia. He said public opinion in Ukraine remained divided on the issue.

"Well, it's not on the agenda, and there is no political consensus and no consensus in Ukrainian society on that," he said.

He said Ukraine needed "intense interaction, intense cooperation" with the Western alliance. He added: "It's important in the sense of security and it's important in the sense of reform for our defense and security sector." – Reuters