The first official invitations came during the 2019 G20 Osaka summit, with invitations going to US President Donald Trump, French president Emmanuel Macron, German chancellor Angela Merkel and Chinese leader Xi Jinping. The invitation to President Trump was reiterated in a phone call with Putin later that year. However, President Trump would later decline the invitation in a diplomatic cable to Moscow, sending National Security Advisor (United States) Robert O'Brien, to attend on his behalf.) In December 2019, an official invitation was sent to President Recep Tayyip Erdogan of Turkey by the Russian Embassy in Ankara. President Putin has also at various times invited multiple heads of state from the CIS and the CSTO.