Donald Trump’s attempt to secure a major diplomatic victory have been derailed after a politician travelling to a White House summit was charged with war crimes. The US president had hoped to bring the long feud between Serbia and Kosovo to an end by hosting a peace summit between the countries’ respective presidents this weekend. But as he was about to head to Washington Kosovo’s President, Hashim Thaci, was accused of being “criminally responsible for nearly 100 murders” by a special international prosecutor in The Hague and cancelled the trip. The politician is also accused of torture and enforced disappearances including those of political opponents. Mr Thaci has denied any wrongdoing and did not immediately comment on the indictment. His spokesman confirmed that he was heading to Washington at the time it was made public. The meeting on Saturday had been organised by Richard Grenell, the US ambassador to Germany who is also Mr Trump’s Balkan peace envoy. The allegations appear to be specifically timed to derail Mr Trump’s efforts at finding a solution a long-running issue in the Balkans. Kosovo had previously been part of Serbia but in 2008 Mr Thaci declared it independent and became its first prime minister. A peace deal could have given Mr Thaci greater political prominence and made it more difficult to prosecute him. The prosecutor’s office said it was taking the unusual step of making the charges public before the White House meeting because of Mr Thaci’s repeated efforts to “obstruct and undermine” the court. However, the indictment does cause a problem for an agreement being signed with Serbia as Mr Thaci was understood to be amenable to a deal to potentially avoid being summoned by the court. The European Union has also been pushing for peace talks but these are now likely to be postponed indefinitely. Serbia has never recognised Kosovo’s status as a country after it broke away from Belgrade following a murderous secession conflict in 1999. Serbia’s refusal has hampered its efforts to join the EU and Kosovo is not recognised by major international bodies, including the United Nations. There have also been allegations that Mr Thaci was the leader of a criminal gang linked to the Kosovo Liberation Army, which was involved in drug, gun and human organ trafficking. Today's accusations will be assessed by a judge from Kosovo Specialist Chambers, which has jurisdiction over war crimes, who will decide if the charges can be proved beyond reasonable doubt before it goes to trial. The Kosovo independence war cost more than 10,000 lives and only ended after a Nato air campaign. Mr Thaci has held senior political positions in Kosovo since the war.