Russian President Vladimir Putin said on Thursday that the threat of nuclear war should not be underestimated, but that he hoped that common sense would prevail.
Speaking at his annual news conference, Putin said it was hard to predict what the consequences would be of a US withdrawal from the landmark Intermediate-range Nuclear Forces Treaty, signed in 1987.
Putin said on Tuesday that the Russian state atomic energy firm Rosatom would start the construction of two new reactors at the Paks power nuclear plant in Hungary soon.
Hungary plans to expand its Paks nuclear power plant and build two Russian VVER 1200 reactors.
Putin made the comments standing beside Hungarian Prime Minister Viktor Orban following talks in Moscow.
Orban told reporters that they had agreed on gas supplies for 2020.