With a chance to make a better second impression in the Oval Office, gratitude diplomacy was front and center for Zelenskyy. In addition to thanking the president six times, Zelenskyy extended gratitude to Melania Trump for personally writing to Russian President Vladimir Putin to think about the Ukrainian children and urge peace.

President Donald Trump is scheduled on Monday to welcome Ukrainian President Volodymyr Zelenskyy to the White House for a high-stakes meeting as the U.S. president pushes for a deal to end Moscow's war on its neighbor. A host of European leaders will join the pair.