Former Soviet leader Mikhail Gorbachev on Saturday urged Russian President Vladimir Putin and new U.S. President Joe Biden to push for deeper restrictions on nuclear weapons.
Tensions soared between the two nations under previous U.S. leader Donald Trump, fuelled by allegations of sweeping cyberattacks and a litany of other disagreements.
But soon after Biden took office, the two powers extended a pact that limits each side to 1,550 nuclear warheads, which Putin hailed as a positive development.
Gorbachev told the Interfax news agency that the two leaders — who spoke by phone after Biden's inauguration last month — should meet and discuss further arms curbs.
"I believe that it is imperative that the presidents meet. Experience shows that it is necessary to meet and negotiate," he said.
"It is clear that the main thing is to avoid nuclear war. Since such a problem must be avoided, it is impossible to solve it alone, it is necessary to meet.
"If the desire to achieve disarmament and to strengthen security prevails, so much can be accomplished."
Earlier this year, the 89-year-old urged the two sides to repair relations, saying that the current situation was "of great concern."
He said that once the New START nuclear accord is extended "a more ambitious treaty" could be negotiated.
Under Trump, Washington withdrew from two major international accords — the Iran nuclear deal and the Open Skies treaty — and pulled out of a centrepiece arms control agreement with Russia, the Intermediate-Range Nuclear Forces (INF) treaty.