Public frustration over Japan’s slow vaccine rollout is intensifying after it emerged the European Union approved the export of more than 50 million COVID-19 shots to the country this year, the most among nations the bloc is shipping to.

The EU said on Monday that it had authorized some 52.3 million doses made in European factories by companies including Pfizer Inc. and Moderna Inc. for export to Japan, the highest volume among all 43 countries to which vaccines have been shipped.

The large number of doses has struck a nerve among the Japanese public because government officials have oft cited supply bottlenecks as one reason for the slow rollout. Pressure is growing on Prime Minister Yoshihide Suga’s government to accelerate an effort that’s given out doses enough for just 1.3% of its population, the lowest among the 37 members of the Organisation for Economic Co-operation and Development, according to Bloomberg’s vaccine tracker. That compares to 37% in the U.S. and nearly 36% in the U.K.