By M. Bilal Kenasari

WASHINGTON

The top U.S. diplomat for Europe said Tuesday that hundreds of Russian soldiers have been killed since the start of the crisis in Ukraine.

"It's pretty difficult to have a completely accurate assessment, given Russia's efforts to mask its dead," said Assistant Secretary of State Victoria Nuland. "I can't speak to more than 400 or 500 at the moment.”

Nuland testified before the House Foreign Affairs Committee while Republican and Democratic continued to pressure the White House to support Ukraine with weapons to defend itself against pro-Russian separatists attacks.

Crimea is suffering severe hardship, according to Nuland.

"Today Crimea remains under illegal occupation and human rights abuses are the norm, not the exception, for many at risk groups there," she said.

"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," Nuland added.

Following a Feb. 12 cease-fire agreement between Ukrainian forces and pro-Russian separatists in Minsk, the U.S. released a series of images that showed Russian heavy equipment inside Ukraine, although the agreement stipulated the withdrawal of heavy weaponry from combat areas.

“In the last few days, we can confirm new transfers of Russian tanks, armored vehicles, heavy artillery and rocket equipment over the border to the separatists in eastern Ukraine," Nuland told the committee.

Despite the evidence, Moscow denies arming the separatists.

More than 6,000 victims have lost their lives in the conflict since last April, according to the UN.