Most of them were Kosovar Albanians killed by Serbian forces, often in mass killings for which few Serbs have been responsible. But more than 2,000 Kosovar Serbs, Albanians and Roma were killed by NATO bombs or by Kosovar guerrilla groups, such as the Kosovo Liberation Army, which Thaci helped lead.
Mr. Thaci’s office declined to comment on the charges, which include murder, persecution, and torture, but has historically denied similar claims. Another politician named in the indictment, Kadri Veseli, who heads a party founded by Thaci, issued a denial on Wednesday.
The postponement of the summit culminates an eventful month for Grenell and his career in foreign policy.
Between February and May, he was Acting Director of National Intelligence for President Trump, serving simultaneously as the U.S. Ambassador to Germany, a role he resigned in May, and also as Special Presidential Envoy for the Serbian-Kosovar peace negotiations, a role he has maintained .
During February and March, he became an increasingly divisive figure in Kosovo because he put severe pressure on Kosovar politicians while making few demands on Serbia, an ally of Russia.
Most controversially, it was perceived that he had taken sides in a political dispute between Thaci and Albin Kurti, then Prime Minister. After Grenell spoke out against Kurti, the latter was abandoned by his coalition partners, leading to the collapse of his government and causing a constitutional crisis in Kosovo.
In May, Mr. Grenell was criticized for politicizing the office of the director of national intelligence when he declassified documents related to Mr. Trump’s former national security adviser, Michael T. Flynn.
And this month, it drew bipartisan concern after leading the push to withdraw thousands of US troops from Germany, a move critics saw as detrimental to American military planning.
