Republican presidential candidate Marco Rubio today said the U.S. is “barreling toward a second Cold War” with Russia. According to Rubio, Russian President Vladimir Putin is trying to “divide” Europe.

“He’s trying to destroy NATO,” Rubio said during an appearance in Cedar Falls last night. “He’s challenging the influence of the United States all over the world.”

During an “Americans for Peace, Prosperity and Security” forum in Cedar Rapids over the noon hour today, Rubio said President Obama is failing “the test of leadership” against Putin.

“Let me tell you what happens in a world where America is weaker,” Rubio said, “the world gets chaotic and dangerous.”

Rubio has been calling Putin a “thug.”

“I love this, you know he was asked on ’60 Minutes’ the other night, verbatim, they said: ‘Marco Rubio says you’re a gangster.’ He said: How can I be a gangster? I worked in the KGB,'” Rubio said in Cedar Falls and the audience laughed. “I’m not making that up. He really said that.”

Rubio, who is wrapping up a two-day campaign swing through Iowa, today promised that if he’s elected president, he’ll “move to isolate Russia” by refusing to issue travel visas to Russian officials and proposing economic sanctions against Russian corporations.

Republican presidential candidate Ben Carson is also campaigning in Iowa today. This morning, Carson said it’s time for a “no fly” zone along the Turkish border with Syria, so U.S. and Russian fighter jets aren’t crossing paths in Syria.

“If the two forces are together, there’s a greater incidence of an international incident that could escalate,” Carson said.

President Obama needs to “step it up a little bit,” Carson said, and tell Russia’s president the U.S. military “will maintain” its battle plan against ISIS in Syria.

“If I were Obama, I would call Putin and I would say, ‘We need to sit down and talk immediately,’ and I would let him know that we’re not backing off,” Carson said. “We’re not restricting the flights of our jets. We’re not respecting any new boundaries in the water.”

The U.S. needs to “reestablish” a missile defense system, Carson said, and deploy more troops in key areas around the globe.

“Putin has very great aspirations, not just in Syria, but globally,” Carson said. “And we need to put a strong front against him everywhere. I mean, you know, throughout the Baltic basin.”

Carson made his comments during taping of the “Iowa Press” program that airs tonight on Iowa Public Television.