Russian President Vladimir Putin and his U.S. counterpart Joe Biden may meet in June, RIA news agency reported on Sunday, citing a Kremlin aide, amid simmering tensions between Moscow and the West. The foreign policy adviser, Yuri Ushakov, said a firm decision on the meeting has not been taken yet. "We will take a decision depending on many factors," Ushakov, the Russian ambassador to the United States from 1998 to 2008, was quoted as saying. Separately, Russian Foreign Minister Sergei Lavrov, cited by RIA, said on Sunday that Biden"s proposal for the summit has been received "positively" and is now under consideration. Russia"s Kommersant daily, citing unnamed sources, said Biden had offered Putin to meet on June 15-16 in a European country. The Kremlin did not immediately respond to a Reuters request for comment. Putin and then U.S. President Donald Trump held a summit in Helsinki in July 2018. Earlier this month, Biden called on Putin to reduce tensions stirred by a Russian military build-up on Ukraine"s border and proposed a summit to tackle a raft of disputes. read more The Kremlin said at the time that a summit would be contingent on U.S. behaviour, reportedly telling Washington to scrap a plan to impose new sanctions on Russia. read more Russia-U.S. ties slumped to a new post-Cold War low last month after Biden agreed when asked in an interview if he thought Putin was a "killer" and Moscow recalled its ambassador to Washington for consultations. Despite Moscow"s protests, the United States this month imposed a series of new sanctions against Russia for alleged interference in the 2020 U.S. election, cyber-hacking, bullying Ukraine and other acts it deemed malign. Putin took part in a virtual climate summit hosted by Biden last week.