White House to brief lawmakers on 'serious national security threat' related to Russia

House Intelligence Committee Chairman Mike Turner, R-Ohio, released an unusual statement Wednesday warning of a "serious national security threat" without providing additional details, pre-empting what the White House said was a planned briefing for congressional leaders.

Four sources with knowledge of the issue told NBC News that the threat is a Russian military capability.

President Joe Biden has been tracking the national security threat and directed White House national security adviser Jake Sullivan to engage congressional leaders, according to two U.S. officials.

White House officials conceded the matter is “serious” but there are