The US is worried by Iran's nuclear intentions, not any new weapons systems it has developed, State Department spokesman Philip J. Crowley told MSNBC News on Monday."I don't think that any one weapon system is going to tip the balance one way or another," said Crowley. "[But] we've made clear that Iran having a nuclear capability would set off an arms race within the region." He added, "We want to do everything we can to forestall that."RELATED:Iranians begin fueling reactor Israel 'too weak to face Iran'Crowley made his remarks in response to Iranian announcements on Monday and Sunday that its domestic arms industry successfully new missile assault boats and unmanned, long-range bombers.The beginning of production came as part of Iran's "government week," in which the Islamic Republic traditionally unveils its most recent technological advancements.IRNA on Monday said that the Zolfaqar missile-launching vessel can be used for patrol as well as attack operations, having a "high destructive power."On Sunday, Iranian President Mahmoud Ahmadinejad introduced an unmanned drone bomber which he dubbed the "ambassador of death."Speaking to a group of officials Ahmadinejad said, "The jet, as well as being an ambassador of death for the enemies of humanity, has a main message of peace and friendship."The goal of the aircraft is to "keep the enemy paralyzed in its bases," he said, adding that the jet is for deterrence and defensive purposes.The president championed the country's military self-sufficiency program, and said it will continue "until the enemies of humanity lose hope of ever attacking the Iranian nation."Associated Press contributed to this report.