Tonight, millions of people on alert as wildfire smoke sweeps through much of the country.

Smoky skies prompting air quality concerns across the upper Midwest has more than a dozen wildfires burn in Canada.

The smoke expected to reach deep into the United States all the way down to Florida.

Meanwhile, out west, cities like Las Vegas and Sacramento,

racing for record heat.

In the south, millions at risk for dangerous storms

and possibly tornadoes were tracking it all.

President Trump now threatening to double tariffs

on steel and aluminum imports

and a growing mystery at the White House,

who's impersonating the president's chief of staff?

Hundreds of thousands of immigrants now at risk of being deported.

The latest fallout from the major Supreme Court ruling.

Hamas responds to the latest Gaza ceasefire proposal.

The latest on peace efforts in the region tonight.

The start warning from the Defense Secretary.

A Chinese invasion of Taiwan could be imminent.

Our team with a rare look at how it's preparing for war.

The new travel alert about measles, cases surging, the CDC sounding the alarm,

what you need to know before you fly this summer.

A home run in the sports world, how Japanese baseball superstars are captivating fans.

And there's good news tonight about the next chapter right here at NBC Nightly News.

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