Moscow ? Russian natural gas monopoly OAO Gazprom promised Monday to boost the amount of gas it ships to European customers through Ukraine, claiming that country was stealing gas intended for the winter-bound continent.

The state-controlled company halted deliveries to Ukraine on Sunday because Kiev had refused to meet its demands for a fourfold price increase. Gazprom said after the cutoff to Ukraine that it would continue shipping full supplies to its European customers, about 80 percent of which goes through pipelines crossing Ukraine.

Despite that promise, within hours of the reduction of gas going into the pipes, other countries began reporting pressure falloffs. Russia said Ukraine was stealing gas; Ukraine denied that.

An array of European countries on Monday called on Russia and Ukraine to work out the dispute. About one-quarter of Europe’s gas comes from Russia and the standoff raised fears of serious gas shortages as Europe suffers through a cold winter.

Ukrainian Foreign Minister Borys Tarasiuk held telephone talks with European Union foreign policy chief Javier Solana and called for international experts to become involved, a ministry statement said.

“We have taken all necessary measures for Europe to receive gas in the full quantity. By tomorrow evening full connections with Europe will be restored,” Gazprom deputy chairman Alexander Medvedev said late Monday.