AMNA NAWAZ: Today, exercises between the American and South Korean militaries began as scheduled, even after President Trump demanded they be scaled back.

This weekend and again today, the president said what he called war games were unnecessarily provocative and a challenge to North Korean leader Kim Jong-un, despite recent praise of South Korea by the administration.

Nick Schifrin joins me now here for more.

So, Nick, tell us more about these exercises and what exactly the president is calling for here.

NICK SCHIFRIN: So, these are annual U.S.-South Korean military exercises called Ulchi Freedom Shield involving tens of thousands of troops.

They started today what the U.S.

military calls a -- quote -- "defensive opportunity" to strengthen U.S.

and South Korean readiness.

They have been held for 50 years designed to deter North Korea.

But that is not how President Trump sees it.

He said they send a - - quote -- "inappropriate and hostile message to an unthreatening and respectful North Korea."

President Trump raised the possibility of restarting diplomacy with Kim Jong-un posting this 2019 photo from the demilitarized zone, writing: "Kim Jong-un and I get along great."

And, this afternoon, the president posted this meme of Kim calling President Trump: "Hey Donald, we cool, right?"

The president's criticism instead today fell on his ally, South Korean President Lee Jae Myung, calling him out over Iran.

Take a listen to... DONALD TRUMP, President of the United States: I called him, I said, would you like to give us a little hand?

We don't need help with Iran.

But if you would like, give us a hand with Iran.

He said, no thanks.

And I said, wait a minute.

We have 39,000 soldiers over there guarding you from Kim Jong-un, your next-door neighbor.

And you're not going to help us on a very easy military operation in Iran?

That's strange.

No, no, we'd rather not get involved.

I see.

Well, why are we involved in helping you?

NICK SCHIFRIN: So, Amna, it's a page out of the president's first-term playbook, joint exercises with South Korea, complaining about South Korean burden-sharing, while publicly messaging Kim Jong-un, let's talk.

AMNA NAWAZ: So we have heard that from President Trump in the U.S.

What have we heard from South Korean officials in response?

NICK SCHIFRIN: South Korea's response was muted.

The president's office in Seoul said that they were reviewing Trump's comments and that they would discuss helping the U.S.

over Iran.

They also said that they wanted a better U.S.-North Korea relationship.

And that is the irony, that the very South Korean administration that the president, President of the United States Donald Trump, is criticizing South Korea over is the diplomacy that South Korea's president, is the diplomacy that South Korea's administration wants the U.S.

to have.

Take a listen to Frank Jannuzi, the president of the Mansfield Foundation, which advocates for diplomacy.

FRANK JANNUZI, President and CEO, Maureen and Mike Mansfield Foundation: I think what is striking about what happened over the last 24 hours is that it appears to have been a move that took our South Korean allies by surprise.

And so these moves are always best when they are coordinated closely.

For the military planners on the peninsula, these exercises are at the core of our ability to deter North Korean aggression.

The United States and South Korea view these exercises as defensive in nature and essential to deterring North Korean aggression and to be prepared.

NICK SCHIFRIN: But North Korea has always seen these exercises, Amna, as provocative, accusing the U.S.

of planning strikes against North Korea's leadership.

And just this week, in fact, Pyongyang launched more missiles, as it almost always does before these exercises begin, following other tests earlier this year of new weapons.

Take a listen to Jennifer Kavanagh.

She is the director of military analysis for Defense Priorities, which advocates for restraint in U.S.

policy.

JENNIFER KAVANAGH, Defense Priorities: When the United States conducts what adversaries consider to be provocative exercises close to their borders, rather than being deterred, they increase their military spending, their own military activities in their region by conducting additional exercises of their own, by increasing pressure on neighbors, by test-firing or experimenting with new weapons.

My view is that South Korea should be defending itself.

And to that extent, having the United States and South Korea training together is unnecessary.

Instead, the United States should be pushing South Korea to carry out these activities on its own without U.S.

support.

And that's the baseline that South Korea should be preparing for.

NICK SCHIFRIN: Kavanagh actually argues that reducing exercises is a small step, Amna, compared to, for example, troop withdrawals or reducing U.S.

commitment to South Korea, of course, threats the president has also made against South Korea.

AMNA NAWAZ: Nick, go back for a second to the public messages to Kim Jong-un you mentioned earlier.

Is there any sign that North Korea is actually interested in that diplomacy?

NICK SCHIFRIN: Publicly, no.

As far as we can tell, North Korea is not interested in talking, especially about denuclearization.

And it's in a much stronger position than it ever was during Trump's first term.

China and Russia have stopped adhering to U.N.

sanctions on North Korea.

Russia is believed to be providing technology to North Korea, improving its missiles.

In fact, Ukrainian President Volodymyr Zelenskyy, who has received North Korean ballistic missiles fired by Russia, says that they have become 300 times more accurate just in the last year-and-a-half, thanks to that Russian technology.

Listen to Frank Jannuzi again.

FRANK JANNUZI: This means that North Korea is going to play hard to get.

And if Trump is serious about opening up channels to North Korea, he's going to have to come bearing gifts.

And that's a very uncomfortable position for a U.S.

president to be in, in negotiating with North Korea.

NICK SCHIFRIN: But, clearly, President Trump is interested in restarting that diplomacy, Amna, and is doing so by publicly criticizing his ally South Korea and calling for these exercises to be scaled back.

AMNA NAWAZ: Nick Schifrin, thank you very much.

NICK SCHIFRIN: Thank you.