Gen. Joseph Votel, Commander of the US Central Command, testifying Wednesday to the House Armed Services Committee about the security challenges in the Greater Middle East. Source: House TV

The nation's top military official in the Middle East on Wednesday said Iran is one of the greatest threats to the U.S. today and has increased its "destabilizing role" in the region. "I believe that Iran is operating in what I call a gray zone," Commander of the U.S. Central Command, Army Gen. Joseph Votel, told the House Armed Services Committee in testimony Wednesday. "And it's an area between normal competition between states — and it's just short of open conflict." The general said Iran is exploiting this area in a variety of different ways, through things such as "lethal aid facilitation," the use of "surrogate forces" and cyber activities, among other things. He also believes Iran poses "the greatest long-term threat to stability" in the entire region. U.S. Central Command is responsible for U.S. security interests in an area stretching from the Persian Gulf region into Central Asia. It includes more than 80,000 soldiers on land, sea and air as well as the ongoing campaign to defeat Islamic State in Iraq and Syria (or ISIS) as well as the Taliban in Afghanistan. "We need to look at opportunities where we can disrupt [Iran] through military means or other means their activities," he said. "We need to look at opportunities where we can expose and hold them accountable for the things that they are doing."

Votel said he gets regular reports on Iran's use of boats to harass U.S. military and others in international waters off its coast, with around 300 incidents in the past year alone. Some, he said, could be considered "unprofessional" or "unsafe." "We are paying extraordinarily close attention to this, but I feel very confident in our ability to protect ourselves and to continue to pursue our missions," he said. That said, the general conceded, "Iran has a role in the region. I want to be clear that we think differently about the people of Iran than we think about the leadership of Iran — the Revolutionary Council that runs Iran. Our concern is not with the people of Iran, it is with their revolutionary government." Meanwhile, the CentCom commander also responded to questions about reports the U.S.-led coalition air strikes against ISIS fighters contributed to the deaths of nearly 200 Iraqis in a western Mosul neighborhood on March 17. "We are doing everything humanly possible to prevent these kind of events and incidents from occurring as a result of our operations," said the general.

A man points towards the fighting as they walk through an area that was affected by a reported coalition air strike in the al-Jadida neighborhood of Mosul, Nineveh Province, on March 24, 2017. Marcus Yam | Los Angeles Times | Getty Images

The U.S. military is assessing and conducting an initial review of the Mosul circumstances, Votel said. U.S. officials visited the Mosul incident site Tuesday to gather both "additional evidence and perspective on the situation," he added. He also dismissed reports that the high Mosul casualty count may have been somehow due to a change in administration policies about military activities in civilian areas. "This was a very dynamic situation," Votel said of the airstrike. "So this wasn't a deliberate target or anything else. This was an evolving combat situation." The general said the military has a standardized process in place on how it looks at such cases and will pull together information from various sources in conducting the Mosul probe. One of the many things he said the investigators will look at is the "intelligence that was provided to the us by the Iraqis." Even so, he added there's a "fair chance" that the U.S. coalition strike targeting ISIS fighters may have also contributed to the high casualties, echoing a comment made Tuesday by Army Lt. Gen. Stephen Townsend, the U.S. commander on the ground in Iraq.

A fighter of the Islamic State of Iraq and Syria, or ISIS, holds a flag and a weapon. Reuters

Votel also reiterated a point made by Townsend that the munitions used in Mosul "should not have created the effects that have been observed," such as the collapse of entire buildings. He said the probe will look at whether "other things contributed to that as well." "I would just suggest that everyone be cautious," said Rep. Mac Thornberry, the House Armed Services chairman (R-Texas) in opening remarks about the Mosul civilian casualties. "In a dense urban environment there might well be civilian casualties. But we also know for certain that ISIS uses innocent civilians as human shields and that they can arrange civilian deaths to further their misguided narratives." Elsewhere, the CentComm commander also provided an update on the fight against the Taliban in Afghanistan. "We are at a stalemate right now," he said. "It is generally in favor of the government of Afghanistan. But stalemates have a tendency to decline over time so I think we do have to continue to support this [fight]." Two missions remain in Afghanistan — the military's counter-terrorism mission and NATO mission to train, advise and assist Afghanistan's military forces, Votel said. The counter-terrorism mission is "going pretty well," although the NATO mission is one where "we ought to consider looking at our objectives here and how we continue to support that mission going forward," he said. Watch: Saudi foreign minister on Iran threat