America will remain Iran's enemy regardless of any nuclear deal struck with world powers, a senior Iranian military official said Sunday.

"The U.S. might arrive at some agreements with us within the framework of the Group 5+1 (the U.S., China, Russia, Britain, France plus Germany), but we should never hold a positive view over the enemy," Iranian Ground Force Commander Brigadier General Ahmad Reza Pourdastan was quoted as saying by Iran's Fars News Agency, reported RT.

"Our enmity with them is over the principles and is rooted because we are after the truth and nations' freedom, but they seek exploiting nations and putting them in chains," he added.

Negotiators from the six world powers and Iran are currently in Vienna making a last ditch attempt at a nuclear accord before Tuesday's deadline. A final deal is expected to involve Tehran agreeing to halt what is widely believed to be a nuclear weapons program in exchange for relief of sanctions that have devastated its economy. Iran maintains its nuclear program is only for peaceful purposes like electricity generation.

Secretary of State John Kerry said Sunday that negotiators were still aiming for the July 7 deadline, which was set after missing a June 30 deadline last week, though other Western diplomats said it could be extended again to July 9, reported Reuters.

While Kerry said negotiators "have never been closer" to reaching a deal, "this negotiation could go either way" he warned, adding that it's time for Iran to make some "hard choices."

"We have in fact made genuine progress (but) we are not yet where we need to be on several of the most difficult issues," Kerry said. "This is something that the world will analyze. We want a good agreement and only a good agreement."

One of the main issues reportedly holding up the deal is a dispute over United Nations sanctions on Iran's ballistic missile program, as well as a broader arms embargo that Iran wants lifted, according to The Wall Street Journal. Diplomats still need to determine what course of action to take if Iran does not uphold its end of the deal. Gaps also remain regarding how to guarantee that nuclear inspectors have access to Iran's sensitive nuclear sites, and an agreement still needs to be reach on when Tehran will be allowed to restart its advanced nuclear research programs, according to NBC News.