Lithuania, a eurozone Baltic state, has repeatedly said construction of the plant 20 kilometres (12 miles) from its border does not meet safety standards, a claim rejected by Minsk.

Skvernelis said Lithuania was ready to ensure gas supplies to Belarus for a proposed gas power plant through its Baltic LNG terminal and a planned gas link between Lithuania and Poland.

"The suggested alternative would benefit the Belarussian economy and would open a new page not only in our bilateral relations but also in Belarus-EU relations," Skvernelis said in a statement.

His advisor Deividas Matulionis told AFP that Skvernelis signed the letter on Thursday, which the Lithuanian embassy in Minsk will deliver to the Belarussian government in the coming days.

The Lithuanian opposition dismissed the offer as a publicity stunt in the service of Skvernelis's candidacy in the May presidential election.

"This is a pre-election game which may lead to a pretext for revoking sanctions rather than stopping the nuclear plant," conservative opposition leader Gabrielius Landsbergis told AFP.

Construction of the facility, located in the northwestern Belarusian town of Ostrovets which is just 40 kilometres (25 miles) from the Lithuanian capital Vilnius, is entering its final stages.

Minsk had said its two reactors, each with a capacity of 1,200 megawatts, would be operational from 2019 and 2020 respectively.

The project was approved by strongman Alexander Lukashenko's government in 2008 and spearheaded by the Russian state energy corporation Rosatom.