IE 11 is not supported. For an optimal experience visit our site on another browser.

KNOW IT ALL: Monday's Top Stories at NBC News

Here's a look at this morning's key headlines.

Good morning. Here are some of the headlines we're following this morning:

1. Mr. Trump Goes to Washington for GOP Establishment Events

Donald Trump is taking his amped-up outsider campaign to the heart of the establishment Monday with a series of events in Washington, D.C., that range from the mysterious to the controversial and even commercial. Read more in POLITICS.

2. 'U.S.A.!' Obama Greeted by Cheers on Historic Cuba Visit

President Barack Obama said Sunday as he visited with U.S. Embassy staff in rainy Havana that he hoped the sight of a U.S. president in Cuba would quickly become something Cubans are used to seeing. "¡Muchas gracias!" the president said at a staff gathering on his arrival in Havana. Read more in NEWS.

3. U.S. Sending More Troops to Iraq After Marine Killed

The United States is sending more Marines to Iraq after an ISIS rocket killed a U.S. Marine and injured several others, the U.S.-led coalition said Sunday. The number of Marines being sent wasn't disclosed. Read more in NEWS.

4. Tennis Boss Ripped for Sexist Comments on Female Players

The head of a major professional tennis tournament came under fire Sunday for disparaging comments about women in the sport, which he later admitted were "in extremely poor taste" and "erroneous." BNP Paribas Open tournament director Raymond Moore said during a morning news conference with reporters Sunday that players in the Women's Tennis Association were "lucky" and that they "ride the coattails of the men." Read more in NEWS.

5. John Kasich Walks Back Merrick Garland Comments

Republican presidential candidate and Ohio Gov. John Kasich walked back from comments he made during an interview on "Meet The Press," saying that that if he becomes president, he would not consider Merrick Garland, President Obama’s Supreme Court nominee, as a potential replacement for the late Justice Antonin Scalia. Read more at MEET THE PRESS.

6. North Korea Launches 15th 'Projectile' in 2 Weeks

North Korea has fired several projectiles into the sea off its east coast, South Korean officials said Monday amid concerns that Kim Jong Un’s regime is preparing to conduct another test of its nuclear weapons. Read more in NEWS.

7. Marvin's World: 9 Lessons From Homeless Winter in NYC

Marvin Bolton, 61, has nearly made it through his first winter of homelessness in New York City. Here's what he and his family learned from the ordeal. Read more in NEWS.

8. 'Boaty McBoatface' Dominates Poll to Name Polar Research Ship

When scientists in the U.K. asked the public to name their new $290 million polar research ship, they expected the name of an explorer such as Sir Ernest Shackleton or a naturalist like David Attenborough to eventually be emblazoned across the vessel's bow. However, they didn't factor in the Brits' oddball sense of humor. Read more in NEWS.