A delegation from Belarus was expected in Moscow on Tuesday and would be presented with a number of proposals, Sharonov said.
Belarus earlier announced it would take the Russian oil monopoly Transneft to court for not paying the tax, authorities in the capital Minsk said.
"Transneft has passed crude oil over the Belarussian border with a view to transit to other countries in violation of the law, without a customs declaration and without paying the relevant taxes," a Belarus customs official was quoted as saying by national radio.
Saturday's announcements were the latest blows in a bitter energy dispute between ex-Soviet Belarus and Russia, its eastern neighbour and one of its few allies.
Belarus applied the transit tax from the start of the year in response to a Russian decision to impose export duties on crude oil that Belarus buys from Russia.
The Russian duty was aimed at clawing back some of the money Belarus makes by refining the oil and selling it on to the West.
Belarus telegrammed Transneft's head Semen Vainshtok, summoning him to appear in court over the company's failure to pay the tax, Russia's Interfax news agency reported on Saturday, but added that the company claimed no summons had been received.