United States president-elect Donald Trump on Thursday called for strengthening and expanding the country’s nuclear weapons capability. In a tweet, Trump said the expansion of the programme was necessary “until such time as the world comes to its senses regarding nukes”.

While Trump did not elaborate on what kind of expansions programme was needed, a spokesperson for the president-elect said the “threat of nuclear proliferation and the critical need to prevent it” were the reasons behind his remarks. Jason Miller said Trump was referring to the threat from “terrorist organisations and unstable and rogue regimes”. “He has also emphasised the need to improve and modernise our deterrent capability as a vital way to pursue peace through strength,” Miller said, according to NBC News.

Later, Trump’s election campaign manager Kellyanne Conway said the president-elect was not “trying to change” US policy on the matter. His remarks came on the same day that Russian President Vladimir Putin said it was necessary for Moscow to “strengthen the military potential of strategic nuclear forces”. “We must carefully monitor any changes in the balance of power and in the political-military situation in the world,” Putin said, according to AFP.

Putin’s remarks came a day after a Kremlin spokesperson said almost all communication channels with the United States were “frozen”, a claim Washington disputed. Kremlin spokesperson Dmitry Peskov said “almost every level of dialogue” between the two countries had ceased, with only the most minimal communication taking place. Tensions between the two countries have grown in recent months because of the Syrian war and the cyber attack on the Democratic Party’s National Committee.