Bulgaria bolstered by NATO forces

US Defence Secretary Lloyd Austin (l) and Bulgarian PM Kiril Petkov.
Bulgarian PM Kiril Petkov (r) and US Defence Secretary Lloyd Austin have agreed troop reinforcements -EPA

The United States has agreed to provide a Stryker mechanised infantry company to Bulgaria under a NATO drive to bolster its eastern flank after Russia's invasion of Ukraine.

"The USA agreed to provide a Stryker company," Bulgarian Prime Minister Kiril Petkov told a press conference alongside US Defence Secretary Lloyd Austin. 

"This is a strong sign to all of our allies in NATO."

Bulgaria, among Moscow's closest allies during the Cold War era but now a NATO and European Union member state, is establishing a battlegroup of up to 1000 troops under the operational command of NATO's Supreme Allied Commander Europe. 

The battlegroup is expected to also host troops from other allied countries.

"I wanted to underscore the importance of the announcement that Bulgaria has established and is leading a NATO multinational battlegroup," Austin said. 

"It is an important step and we fully support it."

Petkov said Bulgaria would continue to send humanitarian aid to Ukraine and take in Ukrainian refugees from the war, but it was not considering sending any weaponry to Kyiv for the time being as his Black Sea country was too close to the conflict.