Ukraine on Tuesday sealed an additional nuclear fuel supply deal with US giant Westinghouse in order to ease its energy dependence on Russia.

Westinghouse Electric Company said it signed a deal in Brussels with Ukraine's Energoatom state nuclear power provider "to significantly increase fuel deliveries to Ukrainian nuclear power plants through 2020."

No figures were immediately available for the value of a deal which Ukrainian Prime Minister Arseniy Yatsenyuk had said would take place.

Nor were there details on the quantities of fuel or number of reactors involved.

The two sides had earlier this year extended their existing cooperation agreement through 2020.

A top Energoatom official said this month that Kiev would like to purchase additional Westinghouse nuclear fuel for 13 of its reactors.

US-based Westinghouse currently supplies fuel for only one of Ukraine's 15 operating units -- the third reactor of the South Ukranian Nuclear Power Plant that is located 300 kilometres (185 miles) south of Kiev.

Ukranian media said Energoatom and the US firm had been cooperating on nuclear fuel supplies since 2000.

The former Soviet republic had previously relied on Russian nuclear fuel manufacturer TVEL.

Relations between Ukraine and Russia have sunk to an historic low as a result of this year's ouster in Kiev of a Moscow-backed president and the subsequent pro-Kremlin rebellion in the country's industrial east.

Ukraine is also seeking to reduce its dependence on Russian natural gas in the wake of a months-long cut in supplies -- the second in five years.

In a statement dated from Kiev, Westinghouse alluded to Ukraine's bid for energy independence, saying Westinghouse "brings diversification of suppliers, global best practices and technology to the Ukraine market."