Tanks and helicopters will be on his agenda when he visits Russia on Tuesday, Prime Minister Prayut Chan-o-cha said on Monday.
The prime minister said he would discuss with Russia as the Royal Thai Army was looking for new tanks and helicopters to replace ageing military equipment.
Gen Prayut said Russian hardware was an option as Thailand was exploring offers with competitive price tags and qualities from other countries. The final decision will be made by a committee set up by the army, he added.
The army has six Mi-17V5 helicopters from Russia to replace Hueys from the United States. The fleet was delivered in 2011. The same model was mentioned by Gen Prayut after a cabinet meeting on Monday.
The prime minister moved forward this week's cabinet meeting to Monday as he would leave for Russia on a three-day working visit on Tuesday, followed by a summit between Russia and Asean until Friday.
Gen Prayut will meet Russian President Vladimir Putin on Thursday ahead of the summit, held to mark two decades of ties between Russia and the Southeast Asian grouping.
News about Thai interest in Russian armaments surfaced in February. Two visits to Russia by Gen Prawit Wongsuwon in February and April this year fuelled speculation that Thailand was keen on military equipment from the European country.
China and Ukraine were other possible candidates for Thailand to buy tanks from, an army source said in February.
Russia is the first country outside Asia that the prime minister visits and he is the first government leader from Thailand to visit Russia in 11 years.
The two countries will celebrate 120 years of diplomatic ties next year.