Washington (CNN)Russia currently poses the greatest global threat to the United States, according to the man slated to be President Barack Obama's top military adviser.
Joint Chiefs nominee: Russia greatest threat to U.S.
"Russia presents the greatest threat to our national security," Gen. Joseph Dunford told the Senate Armed Services committee during his confirmation hearing to be the next Chairman of the Joint Chiefs of Staff.
With its large nuclear arsenal, destabilizing role in Ukraine and threat to NATO nations on its borders, Russia presents a significant challenge to the U.S., even as it faces threats like that of ISIS.
"If you want to talk about a nation that could pose an existential threat to the United States, I would have to point to Russia," Dunford said. "And if you look at their behavior, it's nothing short of alarming,"
Dunford told committee Chairman John McCain, an Arizona Republican, that it would be "reasonable" for the United States to provide sophisticated anti-tank and artillery assistance to the Ukrainian government in response to the situation in eastern Ukraine.
"Frankly, without that kind of support, they're not going to be able to protect themselves against Russian aggression," he said.
Other top U.S. officials, including Defense Secretary Ashton Carter, have also voiced their support for supplying such weapons to Ukraine, but the Obama administration has declined to do so at this point.
When asked about other top challenges, Dunford said China falls right behind Russia because of their capabilities and their behavior throughout the Asia Pacific.
China has been increasingly assertive in the South China and East China Seas, building up artificial islands for possible military use and asserting territorial rights disputed by their neighbors, most of whom are American allies.
While Dunford said China does not currently pose a direct threat to U.S. national security, their activities bear watching. On Friday, State Department spokesman Mark Toner said Secretary of State John Kerry "doesn't agree with the assessment that Russia is an existential threat to the United States, nor China, quite frankly."
North Korea and its ballistic missile capabilities along with the growing international threat of ISIS were also part of the list.
In the Middle East, however, he pointed to Iran as "the most destabilizing element" in the region and "clearly a malign influence."
He pointed to Tehran's support for the Houthi rebels in Yemen and Hezbollah in Lebanon, as well as its involvement in Syria and Iraq.
He added, "They're creating, I think -- they're exacerbating, at least -- the Sunni-Shia sectarianism across the region."
On the recent disclosure by Carter that the U.S. has only trained 60 individuals in Syria to fight ISIS, Dunford said that that low figure had to do with the intense vetting done for the program. He adding that there would need to be a change in U.S. policy before such forces were able to also take on the forces of Syrian President Bashar al-Assad.
One area Dunford was reluctant to discuss was the origin of his nickname, "Fighting Joe." While joking that his wife may have had a part in its creation, he deferred any further discussion on the matter in the open setting.
If confirmed, Dunford, the current commandant of the Marine Corps and former commander of U.S. forces in Afghanistan, will face an uncertain budget environment for the armed services, with the threat of forced cuts through sequestration looming later this year.