Former Russian President Dmitry Medvedev mocked President Donald Trump, saying  the United States had not sent nuclear submarines to Russian shores as Trump had promised.

Trump on Tuesday cast Medvedev as "a stupid person" and said he had moved a "submarine or two" to the coast of Russia. He said in August he had ordered two nuclear submarines to be moved to the "appropriate regions" in response to threats from Medvedev.

"New episode of the thriller series," Medvedev said on X in English. "Trump once again brought up the subs he allegedly 'sent to the Russian shores' insisting they are 'very well hidden."

"As the saying goes, it's hard to find a black cat in a dark room — especially if it’s not there," Medvedev said.