KIEV, Jan. 29 (Xinhua) -- Ukraine's state nuclear power company Energoatom said on Monday it has extended the contract on the import of nuclear fuel with the U.S.-based nuclear power company Westinghouse Electric.

The contract, which was due to expire in 2020, was extended until 2025, said a statement on the Energoatom's website.

The extension of the contract is aimed at diversifying Ukraine's nuclear energy sources, it said.

According to the Ukrainian state-run Ukrinform news agency, the contract envisages that between 2021 and 2025, Westinghouse will deliver nuclear fuel to seven nuclear power reactors in Ukraine.

Currently, Westinghouse supplies nuclear fuel for six out of 15 Ukraine's nuclear reactors and covers about 40 percent of Ukraine's nuclear imports.

The rest 60 percent of nuclear fuel for its power plants Ukraine is importing from Russian state-owned fuel group TVEL.

Ukraine, which relied on Russia for more than 90 percent of its nuclear fuel imports in 2013, has gradually reduced the purchase since the political dispute between Kiev and Moscow in 2014.

As nuclear energy accounts for over half of power generation in the country, Ukraine heavily depends on nuclear fuel for its four nuclear power plants.