President Biden on Tuesday raised concerns with Russian President Vladimir Putin about escalating tensions in Ukraine, where Moscow has taken an aggressive posture.

Biden spoke to Putin over the phone for the second time since taking office and “emphasized the United States’ unwavering commitment to Ukraine’s sovereignty and territorial integrity,” according to a White House readout of the call.

A warning: They also discussed the recently uncovered SolarWinds hack and potential Russian interference in U.S. elections, with Biden warning Putin against cyber intrusions against the United States.