For the first time, the U.S. government confirmed that North Korean forces are in Russia to help fight Ukraine. The U.S. said 3,000 troops have traveled so far in what it called a serious escalation. It also reveals North Korea is expanding its alliance with Russia to take on the U.S. and its allies. Nick Schifrin reports. Watch PBS News for daily, breaking and live news, plus special coverage. We are home to PBS News Hour, ranked the most credible and objective TV news show.  Newsletters: https://www.pbs.org/newshour/subscribe  PBS News podcasts: https://www.pbs.org/newshour/podcasts  Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG  Find more from PBS News at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6  Follow us: TikTok: https://www.tiktok.com/@pbsnews  X (formerly know as Twitter): http://www.twitter.com/newshour  Instagram: http://www.instagram.com/newshour  Facebook: http://www.pbs.org/newshour