The Russian-installed head of the Moscow-controlled part of Ukraine's Donetsk region met Belarusian President Alexander Lukashenko in Minsk on Tuesday and said he had discussed ways of boosting trade.
The visit by Denis Pushilin prompted Ukraine to protest about what it called a "blatantly unfriendly act" by Belarus, a close ally of Russia that allowed Moscow's forces to use its territory as a launching pad for the February 2022 invasion.
Pushilin, writing on Telegram, said he was interested in quarry equipment, tractors and buses as well as building products and furniture.
In return, his region was ready to export grain to Belarus, in addition to existing shipments of sunflower seeds.
The so-called Donetsk People's Republic is one of the four regions in Ukraine that Moscow proclaimed as its own last September in an exercise Ukraine and its allies called a "sham", coercive referendum.
In a statement, the Ukrainian foreign ministry called on Minsk to stop taking "destructive steps" and said it was recalling its ambassador to Belarus for consultations.
(Reporting by Reuters; Editing by Frank Jack Daniel, David Ljunggren and Jonathan Oatis)