Crimea and parts of eastern Ukraine are living under a "reign of terror,"- Assistant Secretary of State Victoria Nuland told the Senate Foreign Relations Committee.

"Even as Ukraine is building a peaceful, democratic, independent nation across 93 percent of its territory, Crimea and parts of eastern Ukraine are suffering a reign of terror – she said. Human rights abuses are the norm in Crimea, not the exception, for many at risk groups there".

She said several groups -- Crimean Tatars, Ukrainians who refuse to surrender their passports, gays and lesbians, journalists and others -- are at risk of persecution.

"This manufactured conflict – financed at Russian taxpayers' expense -- has cost the lives of more than 6,000 Ukrainians, and hundreds of young Russians sent to fight and die in a war their government denies"- Nuland said.

The United States had in recent days welcomed the drop-off in fighting in eastern Ukraine, while maintaining its calls for the full implementation of a ceasefire between Ukrainian forces and pro-Russian separatists that went into effect last month.

Washington nevertheless accuses Moscow of sending arms and other equipment over the Ukrainian border.