AlHijjah 22, 1436, October 06, 2015, SPA -- U.S. Defense Secretary Ash Carter called on Moscow on Tuesday to urgently respond to proposed rules for air-to-air conduct over Syria, as he condemned Russia's "seriously irresponsible and unprofessional" violation of Turkish air space, Reuters reported. The United States and Russian militaries held a secure video conference last week in which Pentagon officials suggested protocols aimed at preventing a mishap, as the former Cold War foes carry out rival campaigns of air strikes in Syria. But since then, Moscow has failed to follow-up, Carter said. "We are waiting for the Russians. They owe us a response," Carter told reporters as he visited Moron Air Base in Spain. "They should come in and do it right now."