Six weeks after the U.S. presidential election, Russian President Vladimir Putin has broken his silence on the outcome and congratulated Joe Biden on his victory in the vote following the Electoral College confirming that the Democratic challenger was the winner.

The Kremlin’s website said on December 15 that in a message to Biden, Putin expressed hope that the two countries could “set aside differences and really promote the solution of many problems and challenges currently faced by the world.”

Putin also wished Biden success, adding that: “For my part, I am ready for collaboration and contacts with you.”

Putin’s spokesman has said the president was hesitant to congratulate Biden before Biden’s victory was officially announced.

The December 14 vote by the Electoral College, which gave Biden 306 votes to 232 for Trump, officially cemented the former vice president’s victory in the November 3 presidential election.

Trump has launched dozens of court cases challenging the results claiming, without showing proof, there was electoral fraud. He has lost almost all of the cases, and failed twice at the Supreme Court to have the results in some key states overturned.

Putin noted that “the Russian-American cooperation based on the principles of equality and mutual respect would meet the interests of the people in both countries and the entire international community.”

Biden is expected to take a tougher stance toward the Kremlin on its human rights record and foreign policies compared with Trump.

He has repeatedly criticized Putin for Russia’s “malign actions,” including invading its neighbors and meddling in foreign elections, and recently called Moscow an “opponent.”

Biden, who topped the incumbent Republican by more than 7 million in the popular vote nationwide, will be inaugurated on January 20, 2021.

With reporting by Reuters and AP