A top US military officer is hopeful that Washington can find a way to resolve a dispute with Turkey over its decision to acquire Russia’s S-400 air defense system. General Joseph Dunford, the chairman of the US Joint Chiefs of Staff, was asked about a Reuters report suggesting the Pentagon could soon pause preparations to deliver advanced F-35 fighter jets to Turkey. “Both the executive branch of our government and legislative branch of our government are going to have a hard time reconciling the presence of the S-400 and the most advanced fighter aircraft that we have, the F-35,” he responded. “We’re hopeful that we can find a way through this, but it is a tough issue,” the Marine general told a security forum in Washington.