"We have plans to decrease our defence spending both this year and next. But this will not lead to any decline in the country's defence capacity," he said during a meeting with other candidates.

"We will not allow for any sort of arms race," he said.

Putin appeared to set the course for exactly that when he unveiled a new generation of "invincible" nuclear weapons during a state of the nation address earlier this month.

He presented Russia's military efforts as a response to recent actions by the United States, which last month unveiled plans to revamp its nuclear arsenal and develop new low-yield atomic weapons.

The announcement came as relations between the global powers plummeted to levels not seen since the Cold War over the conflicts in Ukraine and Syria, and accusations that Moscow interfered in the US presidential election in 2016.

Since then, London has accused Moscow of being behind the killing of a former double agent on British soil, leading to tit-for-tat diplomat expulsions.

On Monday, Putin insisted Moscow would use diplomatic channels to settle differences "with our partners" in an apparent reference to the West.

"From our side, we will do all we can so that the arguments with our (international) partners be resolved by political and diplomatic means," he said.

"It goes without saying that not everything depends on us -- as with love, both sides have to be involved, otherwise there can be no love at all," he said.