China's president in Russia for talks on boosting ties

Chinese President Xi Jinping has arrived in Russia for talks focusing on expanding cooperation with Moscow just as tensions have flared up in U.S.-China ties.

Russian President Vladimir Putin will greet Xi at a Kremlin dinner Monday. Moscow and Beijing will sign dozens of agreements to deepen their cooperation during Xi's two-day trip.

Putin's foreign affairs adviser, Yuri Ushakov, described the current Russia-China relations as "the best in history."

Before heading to Moscow, Xi warned President Donald Trump in a call Monday that "some negative factors" are hurting U.S.-China relations, as tensions soared over the sailing of a U.S. destroyer within the territorial seas limit of a Chinese-claimed island in the South China Sea.

Trump, Putin and Xi will attend the Group of 20 summit in Germany later this week.