The United States has accused Russia once more of "destabilizing" Ukraine and warned of additional sanctions if Moscow fails to meet the terms of a recent ceasefire agreement.

US Secretary of State John Kerry on Wednesday blamed Russian President Vladimir Putin for implementing policies in eastern Ukraine that “violate all the international norms.”

"To date, neither Russia nor the forces it is supporting have come close to complying with their commitments," Kerry told the US House of Representatives Foreign Affairs Committee.

"In Luhansk, and Donetsk, and now in Debaltseve, he has empowered, encouraged, and facilitated directly land grabs in order to try to destabilize Ukraine itself," the top US diplomat claimed.

The US and its allies accuse Moscow of sending troops into eastern Ukraine in support of the pro-Russian forces. Moscow, however, denies any involvement.

Ukraine’s warring sides reached a deal, dubbed Minsk II, at a summit attended by the leaders of Russia, Ukraine, France and Germany in the Belarusian capital, Minsk, on February 11 and 12.

The agreement, which went into effect on February 15, introduced measures such as a ceasefire, a pullout of heavy weapons and constitutional reforms in Ukraine by the end of the year.

Nonetheless, Russia says Kiev and its Western allies have twisted the peace deal.

During Wednesday’s congressional hearing, Kerry also said US President Barack Obama has a number of options against Russia and would make an appropriate decision after consultations with European leaders.

"Plan B is tougher sanctions and additional support to Ukraine," he added. "We’re getting to that critical decision time."

The United States and the European Union have already imposed several rounds of sanctions on Russia, including visa bans and asset freezes.

AHT/AGB