President Donald Trump said Wednesday that a war with Iran would not "last very long" or involve ground troops, as he seemingly dismissed warnings that limited U.S. military action could spiral into a larger conflict.

Trump reiterated his desire to avoid a war but said "we're in a very strong position if something should happen."

"It wouldn't last very long, I can tell you that," he said during a wide-ranging interview on Fox Business.

"I'm not talking boots on the ground," Trump added. "I'm not talking, we're going to send a million soldiers. I'm just saying if something would happen, it wouldn't last very long."

Trump also pointed to his decision last week to call off a military strike after Iran shot down a U.S. surveillance drone.

"I've been very nice to them," he said. "They shot down our drone. I decided not to kill a lot of Iranians. I know a lot of Iranians. I like Iranians so much, and that plays into your decision, too. They're human beings. They're people. I didn't want to kill 150 people."

His comments come amid increasing tensions between the two countries and personal insults between Trump and Iranian leaders. They also come as some U.S. officials and national security experts warn that an administration can never be sure that a military action will not rapidly expand into a new war.

While military analysts assess that the United States would beat Iran in an all-out clash, Tehran possesses ballistic and cruise missiles, air defenses and proxy forces that could kill U.S. troops.

Jim Stavridis, a retired admiral, said Iran also has "exceptionally strong" asymmetric warfare capability, in which a belligerent in a conflict stands up to an opponent with greater abilities

"Cyber, swarm small-boat tactics, diesel submarines, special forces and surface-to-surface cruise missiles are all high-level assets," Stavridis recently told The Washington Post. "They are also very experienced at employing them in the demanding environment of the Middle East. They would pose a formidable challenge to U.S. forces, although we would ultimately prevail in any confrontation of course."

Rep. Seth Moulton, D.-Mass., a Marine Corps veteran who is running for president, said during an interview at The Washington Post on Wednesday that war with Iran would be "very bloody," recalling the accuracy of mortar fire lobbed at U.S. troops by Iranian forces during his second deployment to Iraq.

"I have seen the cost of intervention in very real, human terms. That doesn't mean intervention is off the table. It should always be a threat," Moulton said. "But we better exhaust every other alternative before we put young American lives in danger."

In recent days, Iranian President Hassan Rouhani has described the White House as "mentally crippled" and denounced new sanctions against Iran's supreme leader, Ayatollah Ali Khamenei, as "outrageous and idiotic."

Trump on Tuesday called Rouhani's comments "ignorant" and said that Iran does "not understand reality." Any attack on "anything American," tweeted the president, will bring "overwhelming" U.S. force and "obliteration" of some Iranian assets.

During Wednesday's interview, Trump said he doesn't think that Iran has "smart leadership at all."

"Iran's going down the tubes," he said.