KYIV (Reuters) -U.S. President Donald Trump's Ukraine envoy Keith Kellogg arrived in Kyiv on Monday to discuss security and sanctions against Russia, the head of the Ukrainian presidential administration said. "Defence, strengthening security, weapons, sanctions, protecting our people, strengthening cooperation between Ukraine and the United States — there are many topics to discuss," Andriy Yermak wrote on the Telegram messaging app. Ukrainian President Volodymyr Zelenskiy said in his evening address on Sunday that he had instructed military commanders to present Kellogg with information on Russia's capabilities and Ukraine's prospects. Kellogg will also meet the heads of the Security Service of Ukraine and intelligence services, he added. "Negotiations on further support will take place during the week," Zelenskiy said, adding that he wanted the United States to understand fully what could be done to "compel Russia to (make) peace". Trump said on Sunday he would send Patriot air defence missiles to Ukraine because they were needed to repel intensifying Russian attacks. He is also expected to announce a new plan to arm Ukraine with offensive weapons in a sharp departure from his earlier stance, Axios reported on Sunday, citing two sources familiar with the matter. Reuters could not immediately verify the report. (Reporting by Anastasiia Malenko; Editing by Kevin Liffey)