Washington (CNN) Indiana Gov. Mike Pence on Thursday defended his running mate's statement that Vladimir Putin is a stronger leader than President Barack Obama, calling it "inarguable."

In a sit-down with CNN's Dana Bash at the Ronald Reagan Presidential Library, the GOP vice presidential nominee said Donald Trump was speaking "boldly" as did the 40th president of the United States.

"I think it's inarguable that Vladimir Putin has been a stronger leader in his country than Barack Obama has been in this country. And that's going to change the day that Donald Trump becomes president," Pence said.

But pressed by Bash on the difference between the two nation's governments -- namely that in the US democracy presidents share power with Congress, Pence acknowledged that Trump was not advocating for a dictatorship.

"Donald Trump said last night he doesn't particularly like the system," Pence said in reference to Russia.

The comments were notable because Pence often softens Trump's controversial statements. But in this instance, he doubled down.

Pence was responding to comments Trump made the previous night at a "commander in chief forum" on NBC News.

"Certainly, in that system, he's been a leader, far more than our president has been a leader," Trump said, when asked about his repeated praise and kind words for Putin despite Russia's increasing aggression toward the United States.

Pence also defended Trump's comments that "the generals have been reduced to rubble" under the Obama administration, responding to critics that interpreted those words to mean Trump was putting down the US military.

"I think he was talking about the commander in chief reducing the influence of generals to rubble," Pence said. He added that Trump was describing a "sense that he got recently that in fact our President had not taken all of the counsel of our military advisers in confronting and defeating ISIS."

Trump has been focusing on his national security policy in the past few days, including announcing that his plan to combat ISIS would include ordering military generals to put together a plan to defeat the terrorist group in his first 30 days.

That has stood in contrast with statements Trump made last year that he had a "foolproof" plan to defeat ISIS already.

Pence refused to answer whether Trump has shared his secret strategy with his running mate: "I'll keep our private conversations private," he said.

But he did say that the military could do more under a Trump administration than it has under an Obama administration when asked why the military would have different ideas under Trump than it does now.

"The military commanders serve at the pleasure of civilian authority. The commander in chief makes the call," Pence said. "And I'm confident that our military commanders can bring forward the ideas once the commander in chief makes the mission clear, and Donald Trump has made the mission clear."

Pence refused to say whether Trump would consider sending in significant ground troops to the Middle East, saying he would not "signal to the enemy" his plans.

Comparisons to Reagan's 'humility'

Throughout the interview, Pence compared Trump and Reagan, saying he believes they are similar leaders. He was at the presidential library to give a speech on the comparison between the two men.

"Their styles are different, surely, between Ronald Reagan and Donald Trump, but I think both men are truth tellers," Pence said. "They speak plainly about the failings of the administrations of their time, but they also, I think they both give voice to the aspirations of the American people, that we can be better, we can bet stronger."

He added that comparison applies to one of his favorite adjectives to describe Reagan: "Humble."

As Bash questioned how that word could describe a man with his name on so many buildings, Pence said Trump reveals his "humility" in private.

"Ronald Reagan had his name on a lot of marquees. I think at their very core, both men are the kind of leaders that have a core of humility," Pence said. "Donald Trump is always the first person to say, when we say enormous crowds turn out for rallies ... he's always the first one to say, 'This is a movement. This is not about me. This is about the ideas we're advocating.'"

Debate prep

As the vice presidential nominee, Pence will have his own debate against his Democratic counterpart, Virginia Sen. Tim Kaine, this fall.

Pence said he's preparing "in a very traditional way," despite reports that Trump has eschewed any mock debates or typical debate prep.

"My running mate is a masterful debater," Pence said. "I'm confident he's going to acquit himself well."

As for Pence, he noted that he's been focused on his state as governor of Indiana, and is working to get up to speed on national and international policy.

"We're really taking some time to brush up," Pence said. "I want to make sure that I'm ready to tell Donald Trump's story to the nation."

And he confirmed that his camp has a stand-in for Kaine for mock debates.

"We actually do. I'll leak it to you later," Pence said.

Trump's first debate is September 26, while the sole vice presidential debate will be October 4.