US President Barack Obama will meet with Bulgarian Prime Minister Boyko Borissov at the Oval Office next Monday to discuss a broad range of bilateral and regional issues, the White House said on Monday. As the United States and Bulgaria are NATO allies, the two leaders will discuss Bulgaria's role in the military bloc and its "valuable contributions" to the International Security Assistance Force in Afghanistan, White House spokesman Jay Carney said in a statement. NATO is scheduled to withdraw most of its combat troops from Afghanistan at the end of 2014 after more than a decade of fighting against the Taliban, handing over the lead security responsibility to Afghan security forces. "The president also looks forward to receiving updates on Bulgaria's investigation into the July 18, 2012 terrorist attack in Burgas and ongoing rule of law and judicial reforms," Carney added. Five Israelis and a Bulgarian driver were killed in the attack carried out by a suicide bomber with a fake U.S. driving license at the airport of Burgas.