A Ukrainian government official on Tuesday publicly expressed gratitude for what he called “heavy” weapons the U.S. was sending to his country. The message came a day after Belarusian President Alexander Lukashenko, a staunch ally of Russian President Vladimir Putin, warned that international efforts to bolster Ukraine’s security could result in a “full-scale world war.”

Ukrainian Foreign Minister Dmytro Kuleba tweeted that he spoke with U.S. Secretary of State Antony Blinken “to thank the U.S. for its ironclad support of Ukraine.” He also said that “[m]ore weapons, including heavy, are headed to Ukraine as Russia continues its devastating attacks in the Donbas.”