Western sanctions on Russia have not prevented its support for pro-Russian separatists to date, but they have damaged its economy, U.S. Secretary of State John Kerry said on Tuesday.
''The ruble is at the lowest level in history, I believe, measured against the euro since its introduction in 1991 or so, and clearly the economy is feeling the impact of these sanctions,'' Kerry told reporters in Brussels on Tuesday.
Kerry said: ''We do not want to be in this situation where the only choice available, other than violence, engaging in combat, in order to change illegal international behavior is to inflict a broad-based sanction on any country, on any people.''
NATO accuses Moscow of providing pro-Russian rebels in eastern Ukraine with tanks, advanced air defense systems and other heavy weapons - allegations that Russia denies. The Alliance also said pro-Russian separatists had repeatedly violated the cease-fire agreement signed in September in the Belarusian capital of Minsk.
Russia has the opportunity to make a different choice, according to Kerry.
European Union officials agreed Friday last week to slap sanctions on 13 more Ukrainian pro-Russian separatist individuals and five organizations, bringing the number of people sanctioned to 132 and the number of entities under EU asset-freeze to 28.
However, as the EU has stepped up action against pro-Russian separatists, it remains divided over imposing more economic sanctions on Moscow, which is the 28-nation bloc's main energy-supplier.