The White House press secretary, Karoline Leavitt, is scheduled to speak with the media at 1 p.m. ET on Tuesday, according to the White House, a day after President Donald Trump hosted Ukrainian President Volodymyr Zelenskyy and other European leaders.

Trump complimented Zelenskiy on his black suit in a briefing punctuated with smiles and laughter. It was a much different scene than their chilly meeting in February, when the Ukrainian president's military-style attire in the Oval Office drew ire.

Special U.S. envoy Steve Witkoff says Russian leader Vladimir Putin agreed to allow the U.S. and Europe to offer Ukraine a security guarantee resembling NATO's collective defense mandate.

European leaders said President Trump offered his backing during a call they held ahead of his summit with Russian President Vladimir Putin on Friday.

European shares opened higher and oil prices slid on Tuesday before a key meeting of central bankers and as traders evaluated promising diplomatic signals toward ending hostilities between Russia and Ukraine.

Ukraine's largest mobile operator Kyivstar successfully tested Starlink's Direct to Cell satellite technology, allowing text messages sent directly from smartphones via satellite, as announced by the Ministry of Digital Transformation and Kyivstar parent company Veon.