Ukraine on Sunday accepted a deal on the European Union-led monitoring of Russian gas transit across its territory, opening the way for restarting Russian natural gas supplies to a freezing Europe after a four-day halt in shipments.

Russia wanted the written deal to renew gas shipments suspended amid a bitter contract dispute with Ukraine — a move seen by many as another attempt by Moscow to reassert its clout over Western-leaning former Soviet republics.

Russia said it needs European Union monitors deployed to Ukraine to prevent it from stealing Russian gas intended for Europe. Ukraine hotly denied the claims.

Czech Prime Minister Mirek Topolanek, whose country holds the rotating EU presidency, shuttled between Moscow and Kiev on Saturday to mediate the deal. He finally persuaded Ukraine to accept the monitoring pact during marathon talks that dragged past midnight.

"Nothing prevents Russia now from resuming gas supplies," Topolanek said after Ukrainian officials endorsed the deal.

"We once again have shown our goodwill," said Ukrainian Prime Minister Yulia Tymoshenko, adding that the monitoring mission would uphold her nation's image as an "honest transit country."

Bitter economic battle

Russian Prime Minister Vladimir Putin promised that Moscow will resume gas shipments once the deal is signed and monitors are in place, but also issued a warning to Ukrainian officials.

"Once the monitoring mechanism starts working, we will start gas supplies," Putin said Saturday after the talks with Topolanek. "But if we see them stealing it again and part of the gas is missing, we will again reduce supplies by that amount."

Russia supplies about one-quarter of the EU's natural gas, most of it shipped through Ukraine, and the disruption has come during a harsh winter. At least 11 people have frozen to death this week in Europe, including 10 in Poland, where temperatures have sunk to -25 C.

Ukrainian officials have previously voiced concern the deal would give Russian officials too much access to the Ukrainian gas-transit system.

The EU experts arrived in Ukraine on Friday prepared to act as referees in a bitter economic battle between the two countries states but there were no gas shipments for them to track Saturday, as Russian and Ukrainian officials argued over details of the monitoring pact.