BEIRUT (Reuters) - President Bashar al-Assad said in an interview with AP News broadcast on Thursday that Syria’s war will “drag on” as long as it is part of a global conflict funded and interfered in by other countries.

Syria's President Bashar al-Assad speaks during an interview with NBC News in this handout picture provided by SANA on July 14, 2016. SANA/Handout via REUTERS

“When you talk about it as part of a global conflict and a regional conflict, when you have many external factors that you don’t control, it’s going to drag on,” Assad said.

Syria’s five-year-old war pits Assad, backed by Russia, Iran and Arab Shi’ite Muslim militias against a myriad of Sunni Muslim rebel groups, including some supported by the United States, Turkey and Gulf Arab states.

The conflict has wrought a devastating human toll, killing hundreds of thousands, displacing half the country’s pre-war population of 22 million and included poison gas attacks, starvation sieges and raids on hospitals.

Assad told AP that Russia was not behind a deadly attack on an aid convoy on Monday, for which U.S. officials have said they believe Moscow was responsible.

“Those convoys were in the area of the militants, the area under the control of the terrorists. That’s what they should accuse first: the people or the militants, the terrorists who are responsible for the security of this convoy,” Assad said.

“We don’t have any idea about what happened.”

The United States and Russia have been leading diplomatic efforts to negotiate a lasting ceasefire and have been discussing how to coordinate attacks on militants from the Islamic State and the group formally known as the Nusra Front.

A seven-day ceasefire collapsed last week as violence flared up around the country once again.

Assad cast doubt on the intentions of the United States in Syria, saying it “doesn’t have the will” to fight militants.

“I don’t believe the United States will be ready to join Russia in fighting terrorists in Syria...the United States is not genuine regarding having a cessation of violence in Syria.”

The Syrian government describes all groups fighting against its rule in Syria as terrorists.