US President Donald Trump at a White House on August 1. (Photo: Xinhua/VNA)

In a post on Truth Social, President Trump said the move was intended to prevent an undesirable scenario. He also referenced recent remarks by Dmitry Medvedev, deputy chairman of Russia’s Security Council, who warned earlier this week that the US “ultimatum” to Russia over the conflict in Ukraine could be “a step towards war.”

Trump is now pressuring Russia to speed up ceasefire talks with Ukraine and has threatened additional sanctions - targeting both Russia and its export customers - if a deal is not reached by the August 8 deadline.