Ukrainian Prime Minister Arseniy Yatsenyuk warned in an interview that aired Sunday that Russia is undermining global stability and nuclear nonproliferation efforts amid an ongoing crisis between Kiev and the Kremlin.

Ahead of a visit by US Vice President Joe Biden, he also called for financial and economic support and help modernizing Ukraine's military -- while stopping short of asking for weapons.

"The world has a reason to be concerned about (Russian President Vladimir) Putin's intention(s) because what (the) Russia Federation did, they undermined the global stability," Yatsenyuk told NBC's "Meet the Press" show, in remarks taped Saturday.

"They actually eliminated nuclear nonproliferation programs," he added in reference to the 1994 Budapest Memorandum under which Ukraine handed over its nuclear weapons in return for guarantees of sovereignty from Moscow and Western powers.

"Russia violated this deal, and Russia undermined the entire program of nuclear nonproliferation," Yatsenyuk said.

"And it's crystal clear that for today Russia... is the threat to the globe and the threat to the European Union and a real threat to Ukraine."

With Biden expected in Kiev this week, Yatsenyuk said that, in addition to financial and economic support, the Ukrainian military needed an "overhaul."

However, he refused to be drawn on whether Kiev needed weapons.

"We need to be in very good shape in order to stop Russia, and for this shape we need to have and to get the real support from our Western partners," he told NBC.

"We need financial economic support, we need to modernize the Ukrainian military and to overhaul all structures of (the) Ukrainian defense system."

In the same interview, Yatsenyuk accused Putin of harboring expansionist ambitions.

"President Putin has a dream to restore the Soviet Union, and every day he goes further and further, and God knows where is the final destination," he said.

The Russian ambassador to the United States, Sergey Kislyak, hit back at the accusation.

"Any statements about us having dreams of restoring (the) Soviet Union is a false notion in its very nature," Kislyak said in an interview with "Fox News Sunday."

The exchange comes as pro-Kremlin rebels in east Ukraine appealed for Russian "peacekeepers" to sweep in after a deadly gunfight killed at least two of their militants, shattering an Easter truce and sparking "outrage" in Moscow.