The summit of European Union (EU) leaders, scheduled for September 24-25, has been postponed after European Council President Charles Michel entered quarantine, his spokesman announced on Tuesday. 

The postponement is a blow to Greece and Cyprus, who must now wait until October 1-2 for EU leaders to discuss how to respond to rising tensions in the Eastern Mediterranean over energy resources there.

Michel, who chairs EU summits, tested negative for COVID-19 on Monday, his spokesman said via Twitter, but was following the rules in Belgium, the seat of EU institutions where the summits of EU leaders take place, by going into isolation.

"The president today learned that a security officer, with whom he was in close contact early last week, tested positive for COVID," Michel's spokesman said. "The president is tested regularly and tested negative yesterday. Respecting Belgian rules, he has gone into quarantine as of today."

The EU leaders are scheduled to meet and discuss the single market, industrial policy and digital transformation, as well as external relations. The summit will also be an opportunity to take stock of the COVID-19 situation.

A potential deal on Turkey over a summit dinner that was due for Thursday in Brussels was also billed as the venue to find approval for economic sanctions on Belarus in support of pro-democracy protests there.

EU leaders and ministers have resumed in-person meetings under physical-distancing rules, but EU officials still abide by Belgium's lockdown rules imposed to battle the spread of the coronavirus.

In the week from September 10 to September 16, a total of 7,749 COVID-19 infections were reported in Belgium, whose capital plays host to the EU headquarters, an average of 1,107 new cases per day. 

As the world is in the midst of the COVID-19 pandemic, countries across the globe, including UK, Germany, China, Russia, France and the U.S., are racing to find a vaccine. According to the website of the World Health Organization (WHO), as of September 17, 182 COVID-19 candidate vaccines had been in development worldwide, with 36 already in clinical trials.

(With input from Xinhua, Reuters)