Chinese President Xi Jinping and U.S. President-elect Donald Trump held their first phone talks in four years Friday. According to Trump, he spoke with Xi about TikTok, just hours before the Supreme upheld a law set to ban the social media platform in the United States in less than 48 hours.

Xi after the call said that he and Trump both expressed hope for greater progress in U.S.-China relations, Reuters reported, citing the Chinese state media.

In-depth information regarding the contents of the phone conversation, which took place on Friday (January 17), has not yet been revealed. Trump did post about it on social media, though