The Ukrainian military has had "tremendous success" in fighting back after Russia's invasion, but the Russian military remains strong and the fight between the two nations is far from over, according to former Amb. Michael McFaul.

"Russia has tremendous military capacity still left, and that makes me worried, and frankly concerned, that this war is going to go on for a long time," McFaul told MSNBC's Jonathan Capehart on Friday.

The former ambassador's interview comes on the heels of reports Russia's Vladimir Putin is being misinformed by his advisers about how badly his military is performing in Russia, and McFaul said he is "a little skeptical" about that information.

"We have no way to check our intelligence community, but I wonder about that," McFaul said. "Maybe that is some disinformation game we're playing, about him, and maybe he wants to signal that. But he's upset with his generals, and most certainly, [from] the reporting I read from Russian sources, he's very upset with the way the war is going."

Meanwhile, Russia held its conscription draft this week to bring in 134,500 new soldiers, but McFaul pointed out the draft is "normal standard operating procedure" for the country, which holds its annual military conscription actions April 1.

Ukraine has also continued to refuse to confirm or deny a late-week bombing raid on a fuel depot on Russian soil, but McFaul said he thinks Ukraine did carry out the attack.

"I think that they wanted to demonstrate that war is war, and if you're gonna fuel your planes, and you're going to fuel your weapons, your trucks, across the border from Kharkiv, we're going to strike you where you are fueling your weapons, your trucks, and your automobiles that are striking us," he said.

However, McFaul said he thinks it is "highly unlikely" the Russians will view the attack on their side of the border as a reason to escalate attacks into Poland or other places supplying Ukraine with weapons.

"Let's define escalation," he said. "The Russian armed forces are having an incredibly difficult time fighting against an army that is not as well-equipped as it should be and is not nearly the capacity of the NATO alliance, let alone the most powerful military in the world, the United States of America."

McFaul added, Russia will keep making threats to the allied nations about arming Ukraine to keep worries going about the war escalating.

"I think we should be strong here, and just do what we said what we're going to do, continue to arm them," McFaul said. "The only way there will be peace in Ukraine is if there is a military stalemate."

Meanwhile, the U.S. military Friday said it has canceled a test of its Minuteman III intercontinental ballistic missile to lower nuclear tensions with Russia, and McFaul said he thinks that was the right call.

"I used to work at the White House for President [Barack] Obama and we used to do that from time to time, in terms of when there were tense moments," McFaul said. "We do not want to get into a war with Russia. I completely, 100%, support the president, when he says we're not going to enforce a no-fly zone because that is tantamount to declaring war.

"But anything short of that, I think we need to be doing as much as we can."

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