BERLIN — The European Union released new figures Thursday showing it has exported more coronavirus vaccine doses than it has administered, but leaders meeting for a virtual summit played down the threat of blocking shipments leaving the bloc.

Overall, 77 million doses have been shipped from the European Union since early December, 88 million will have been distributed internally by the end of the week, and 62 million shots have been administered within the bloc, European Commission President Ursula von der Leyen said.

While Europe has exported more than 20 million doses to Britain — no longer an E.U member — the bloc has so far sent fewer than 16 million doses to Germany, which is more populous.

Britain has exported no vaccine doses back to the European Union, according to E.U. officials.

The widening gap has been exacerbated by British-Swedish manufacturer AstraZeneca’s failure to deliver on its targets for E.U. deliveries, prompting the bloc’s executive branch to introduce more curbs on vaccine exports Wednesday. The new rules allow vaccine export decisions to consider reciprocity, a country’s epidemiological situation and its vaccination rate.

“Companies have to honor their contract to the European Union before they export to other regions in the world. And this is of course the case with AstraZeneca,” von der Leyen said, adding the company would have to “catch up” before it could export outside the bloc.

But some leaders — including from the Netherlands and Belgium, which host several vaccine facilities — indicated a reluctance Thursday to invoke the new rules, fearing a possible corresponding disruption to supplies needed in Europe for the manufacturing of vaccine.

“We have very much said that broader consequences have to be taken into account, that we hope it will not be used, it will not be necessary to be used,” Dutch Prime Minister Mark Rutte said in a news conference.

Speaking in the German parliament earlier Thursday, Chancellor Angela Merkel said Europe should continue to export vaccine but also focus on production capacity.

“We see very clearly: British facilities produce for Britain. The United States does not export. That’s why we’re dependent on what can be produced in Europe,” she said, adding that European leaders would need to discuss how to “become more independent.”

The European Union’s new criteria for exports prompted angry responses this week from the government in Britain, where officials fear they could be among the first to be affected. The European Commission and the British government later sought to calm tensions, writing in a joint statement Wednesday that “the third wave makes cooperation between the EU and UK even more important.”

Unlike Britain, the United States has not depended on imported vaccine, but it was — to the frustration of its neighbors — also initially unwilling to share doses with other countries. There have been some signs of a cautious shift in strategy in recent days. The Biden administration said last week it would “loan” some vaccine doses to Mexico and Canada.

In an interview with European broadcaster Euronews this week, Secretary of State Antony Blinken suggested that more such arrangements could be announced in the coming weeks.

President Biden called in to the leaders’ summit Thursday, but there was no statement about vaccine-sharing with Europe.

“We agreed that we have a strong interest in working together to keep global supply chains functioning and to prepare already for the next challenges to come in this pandemic,” von der Leyen said afterward.

She said that in addition to the pandemic, Biden spoke about climate change, economic recovery, technological innovation and democracies defending human rights.

After a year in which the United States largely served as an example for how not to respond to the pandemic, the E.U. summit may have marked a shift. Speaking at a news briefing afterward, French President Emmanuel Macron credited the United States for its quicker vaccine rollout.

“I consider that the United States had been more innovative, more ambitious, they have been able to dream more than us, and they invested very significant sums to innovate faster and stronger,” he said. “And they were right. It must be a lesson.”

The European Union’s sluggish inoculation campaign and a third wave of the virus have prompted public backlash in Europe. But leaders continued to disagree Thursday over what approach to take. Some member states lack supplies, and others are concerned by growing stockpiles that are being linked to vaccine skepticism. The disarray could cost thousands of additional lives in the coming weeks.

Ariès reported from Brussels.