Ukraine's President Volodymyr Zelenskyy is in Serbia for talks on economic ties and security issues. The visit, which included talks with Serbia’s President Aleksandar Vucic on Saturday, is the first by a Ukrainian president in eight years. It came as Russian attacks on Kyiv and its surrounding region killed four people, including a child. Zelenskyy said deliveries of Patriot air defense interceptors had slowed and that the U.S. has agreed to let Ukraine manufacture Patriot systems, but bureaucracy is slowing the process of obtaining licenses.