White House Principal Deputy Press Secretary Josh Earnest has urged Western states to use the gas dispute between Russia and Ukraine to support Kyiv.

"There is an opportunity for us to act with our partners around the world to protect the interests of a sovereign Ukraine," he said.

Earnest said that the situation with Russian gas supplies "shouldn't be used to coerce another nation's political leadership. So that's something that we're concerned about and [that] we're following very closely."

"Access to energy supplies should not be used to inappropriately influence the government of another country," he said.

"The EU has been actively engaged in trying to negotiate a settlement to this dispute between the Russians and the Ukrainians, and we're supportive of that effort and we're hopeful it will continue," he said.

As reported, Russia's OJSC Gazprom imposed a prepayment regime for Naftogaz Ukrainy effective from 1000 on Monday, the day after Russian-Ukrainian gas talks failed to produce an agreement.

"The decision was made due to Naftogaz Ukrainy's chronic nonpayment. Its overdue indebtedness for Russian gas totals $4.458 billion: $1.451 billion for November-December 2013 and $3.007 billion for April-May 2014," Gazprom said.