German Chancellor Angela Merkel is pressing for a solution to the long-running gas dispute between Russia and Ukraine ahead of a meeting of the two countries' energy ministers this week.

Though Merkel noted "small successes" in the overall effort to calm the crisis in Ukraine, she said a long-lasting solution remained far off.

Speaking to business leaders Tuesday, she said the dispute over payments for past deliveries and future gas prices is one of many uncertainties that must be resolved "as quickly as possible."

European Union energy commissioner Guenther Oettinger is brokering a new round of gas talks in Berlin on Friday.

Moscow cut off gas deliveries to Kiev in June.

Merkel said Europe's gas supply is closely linked with Ukraine's "and winter is nearing, so time is pressing."