BELGRADE, Serbia — The European Union started delivering EU-funded coronavirus vaccines Tuesday to the Balkans, a region that wants to join the 27-nation bloc but where China and Russia have already been supplying the much-needed shots and making political gains.

The European Commission last month announced that 651,000 Pfizer-BioNTech doses will be delivered to Serbia, Bosnia, North Macedonia, Montenegro, Albania and Kosovo in weekly instalments from May to August. The vaccines are funded from a 70 million euro package ($85 million) adopted by the Commission in December.

Most of the Balkan countries have struggled to get coronavirus vaccines, except for Serbia, which had launched a successful inoculation campaign mainly thanks to millions of doses of China's Sinopharm and Russia's Sputnik V shots, which have so far not been approved by EU's drug administrator.

Following on the footsteps of Serbia, the other Western Balkan nations have been turning to China and Russia for vaccines as EU nations faced their own vaccine delays.

China's and Russia's vaccine exports to Serbia and elsewhere came with soft-power messages, with politicians praising mutual friendship and criticizing the EU for not coming to the rescue when it was needed the most.

EU enlargement commissioner Oliver Varhelyi, who traveled to the Western Balkans to formally deliver the vaccines, rejected such criticism.

While in Bosnia on Tuesday, Varhelyi pledged that the bloc "will not let down" the West Balkan nations in their fight against the virus.

""The delivery of the vaccines confirms our continuous commitment to provide support, as we have been doing since the outbreak of the pandemic. Stronger together!," he said on the second leg of his 3-day tour of the region.

His trip kicked off in Serbia on Monday and will include stops in Montenegro, North Macedonia, Albania and Kosovo.

Several Balkan nations, most notably Bosnia, heavily relied on World Health Organization's COVAX vaccine program, which distributes vaccine to less developed nations. But COVAX deliveries were significantly delayed among shortages of the shots and some Balkan nations have been struggling to purchase COVID-19 vaccines directly from manufacturers. 

The EU-funded vaccines to the Balkans come on top of those provided by COVAX, where the EU is one of the top contributors with close to 2.5 billion euros.

"We care about this region. Their future lies in the European Union. And this is why we're working to support them as best as we can to deal with the pandemic," EU spokesperson Ana Pisonero said Tuesday in Brussels.