A U.N. tribunal set up to prosecute those behind the 2005 assassination of Lebanese Prime Minister Rafik Hariri said on Wednesday it will have to close after July if it is unable to resolve an acute funding shortage.

"The Special Tribunal for Lebanon (STL) regrets to announce that it is facing an unprecedented financial crisis. Without immediate funding, the Tribunal will not be able to operate beyond July 2021," it said in a statement.