Talks on reducing strategic nuclear weapons must first be conducted between Russia and the US, but the arsenals of Britain and France will ultimately have to be included in negotiations, Kremlin spokesman Dmitry Peskov was quoted as saying on Sunday.
Peskov's remarks come amid a Kremlin proposal to the US this month to voluntarily maintain for a year the limits on deployed strategic nuclear weapons set out in their New START arms control treaty once it expires next year if the US does the same.
White House press secretary Karoline Leavitt said Putin's proposal sounded "pretty good," but the issue was up to US President Donald Trump. The US president has said he wants to open denuclearisation talks with Russia and China.
"Naturally, we have to start talks at the bilateral level. New START is after all a bilateral document," Peskov told TASS.
"But in the long term, you cannot remain abstract with these arsenals. All the more so that these arsenals are a component of the overall problem of global European security and strategic stability."
New START was signed by then-presidents Barack Obama and Dmitry Medvedev in 2010, came into force a year later and was extended in 2021 for five more years after US President Joe Biden took office.
In 2023, Putin suspended Russia's participation, but Moscow said it would continue to observe the warhead limits. Putin this month made his offer to maintain the treaty's limits as Ukraine tries to convince Trump to impose harsher sanctions on Russia over its February 2022 invasion of its smaller neighbour.
Russia and the US have by far the biggest nuclear arsenals in the world. New START caps the number of deployed strategic nuclear warheads at 1,550 and the number of delivery vehicles - missiles, submarines and bomber planes - at 700 on each side.
France and Britain, which were never a party to New START or its precursor treaties, have much smaller arsenals numbering between 250 and 300 warheads each.
(Writing by Ron Popeski; Editing by Lincoln Feast.)