Russia notified the United States before its experimental launch of an intermediate-range ballistic missile (IRBM) targeting Ukraine, the Pentagon confirmed.
"The United States was pre-notified briefly before the launch through Nuclear Risk Reduction channels," Deputy Pentagon Press Secretary Sabrina Singh told reporters.
The IRBM was based on Russias RS-26 "Rubezh" intercontinental ballistic missile model, she said.
Russian President Vladimir Putin said Thursday that his country struck the Pivdenmash aerospace plant in Dnipro in central-eastern Ukraine with a new hypersonic medium-range ballistic missile.
Putin updated Moscow's nuclear doctrine on Tuesday.
The escalation came amid reports that the Biden administration authorized Ukraine to use long-range US missiles to target deep within Russia.
Asked about Putin's remarks that Russia could strike countries who let Ukraine use their missiles, Singh said Washington has observed no changes in Moscows nuclear posture.
"We haven't seen any adjustments that we've observed in their nuclear posture, and we haven't adjusted our nuclear posture in exchange," she said. "What we're focused on is continuing to support Ukraine with what it needs."
