Trump’s national security adviser, Mike Waltz, said the US president is “obviously very frustrated” with Ukrainian President Zelensky. “Some of the rhetoric coming out of Kyiv, frankly, and insults to President Trump were unacceptable,” Waltz said. FRANCE 24's Mark Owen speaks to former NATO Assistant Secretary-General Antonio Missiroli. He says that there has already been a degree of weakening of the US security guarantee within the NATO framework and the credibility of Art.5.