The president faced fierce bipartisan criticism for days after he met with Russian President Vladimir Putin in Finland.
Trump wants to ease tensions between the former Cold War foes and has been solicitous of the Russian strongman despite the United States intelligence community's unanimous conclusion that the Kremlin meddled in the 2016 USA election and was also targeting the upcoming midterms. Paul tweeted that he "was honored to deliver a letter from President Trump to President Vladimir Putin's administration".
The Kentucky Republican says Russian and American lawmakers need to work closer than before, saying the lack of dialogue is the biggest problem between the two countries.
The letter comes three weeks after Trump met with Putin in Helsinki, Finland, sparking a backlash in both parties after his initial refusal to side with the USA intelligence community over Russian denials about meddling in the 2016 presidential election. Trump's top intelligence official, Dan Coats, has said that he is in the dark about what Trump discussed with Putin in their one-on-one meeting in Helsinki.
Kremlin spokesman Dmitry Peskov said that a letter from Trump to Putin had been delivered by diplomatic channels, the Interfax news agency reported.
Trump soon after his summit with Putin had invited the Russian president to Washington this fall, but Trump's national security adviser, John Bolton, later said any meeting would be put off until 2019.
Russian President Vladimir Putin said on July 27 that he was ready to meet USA leader Donald Trump both in Washington and in Moscow.
But the White House didn't offer an explanation on why such a high-level communication between the two leaders was revealed through a senator's office and not the West Wing's press office, which is typically standard protocol.
Paul remained supportive of Trump following the US President's performance during a news conference with Putin in July.
Rand Paul to the Russian leader. Trump said then that he doesn't "see any reason why" Russian Federation would be responsible for the election hacking, accepting Putin's denial over the USA intelligence community's assessment. A reported text of the draft bill published on Wednesday sent Russia's rouble to lows against the dollar last seen in April.