MOSCOW, Nov 17 (Reuters) - Nikolay Patrushev, the secretary of the Russian Security Council, and U.S. national security adviser Jake Sullivan on Wednesday agreed to work on improving mutual relations between the two countries, RIA state news agency reported. The Russian Security Council said the phone talks were constructive and became a part of preparations for future high-level contacts between Russia and the United States, RIA reported. In a brief statement, the White House National Security Council said Sullivan and Patrushev "discussed several issues in the bilateral agenda and regional and global matters of concern. The talks were held in a frank and constructive manner."