White House Press Secretary also warns that Russia may seek to use chemical and biological weapons in Ukraine.

The Energy Department and National Nuclear Security Administration, which maintains the U.S. nuclear weapons stockpile, have evidence that hackers accessed their networks as part of an extensive espionage operation that has affected at least half a dozen federal agencies, officials directly familiar with the matter said.

France has officially acknowledged for the first time that French Polynesians were effectively forced into accepting almost 200 nuclear tests conducted over a 30-year period, and that it is responsible for compensating them for the illnesses caused by the fallout.