US-NATO plan largest military exercise on Russian doorstep

About 25,000 military forces from the United States and 23 other countries will take part in a large-scale military exercise called "Saber Guardian" planned in Bulgaria, Hungary and Romania next month.

In addition, several U.S. B-1B heavy bombers have arrived in Britain in support of two separate multinational exercises planned in the Baltic region and other parts of Europe this month to improve coordination among partner countries.

The U.S. military plans were announced by Stuttgart-based U.S. European Command, which said this year's Saber Guardian exercise - held annually in the Black Sea region since 2013 - was "larger in both scale and scope" than previous exercises.

The news could exacerbate tensions that are already running high between Moscow and Washington.

Russia scrambled a fighter jet on Tuesday to intercept a nuclear-capable U.S. B-52 strategic bomber it said was flying over the Baltic Sea near its border, in an incident that had echoes of the Cold War.