Minsk cites "legitimate risks" in the sphere of national security for its decision to boost defence capabilities insiting that Moscow's nuclear plans would not contravene international non-proliferation agreements.
Belarus said on Tuesday it had decided to host Russian tactical nuclear weapons after years of pressure from the United States and its NATO allies aimed at changing its political and geopolitical direction.
Russian President Vladimir Putin said on Saturday that Moscow would in future look to deploy tactical nuclear weapons in neighbouring Belarus, a staunch ally, escalating a standoff with the West.
The Belarusian foreign ministry justified its decision to cooperate with Russia in a statement on Tuesday, saying Minsk was acting to protect itself from the West.
"Over the last two and a half years, the Republic of Belarus has been subjected to unprecedented political, economic and information pressure from the United States, the United Kingdom and its NATO allies, as well as the member states of the European Union," the statement said.
"In view of these circumstances, and the legitimate concerns and risks in the sphere of national security arising from them, Belarus is forced to respond by strengthening its own security and defence capabilities."
Minsk said the Russian nuclear plans would not contravene international non-proliferation agreements as Belarus itself would not have control over the weapons.
On Sunday, the EU's foreign policy chief Josep Borrell warned that Brussels was ready to impose new sanctions on Belarus if it will proceed with the plan to host Russian nuclear weapons.
"Belarus hosting Russian nuclear weapons would mean an irresponsible escalation and threat to European security. Belarus can still stop it, it is their choice. The EU stands ready to respond with further sanctions," Borrell posted on social media.
Earlier, Putin said the deployment was similar to moves from the United States, which stores such weapons in bases across Belgium, Germany, Italy, the Netherlands and Türkiye, an analogy western allies called "misleading".
READ MORE: EU warns Belarus of more sanctions if Russia nuclear weapons plan proceeds