At the same time, as the head of state stressed, there is no evidence that a foreign power has changed the results or the count of votes in any elections in the United States.
Despite this, the White House said in a statement, foreign powers "have historically sought to use America's free and open political system."
Trump noted that the proliferation of digital devices and Internet communications has created significant vulnerabilities and "increased the scale and intensity of the threat" of foreign interference.
Earlier, the US national security adviser Robert O'Brien said that Washington "made it clear" to China, Russia and other countries that those who try to "interfere" in the American elections will face "extraordinary consequences."
In April, Russian Foreign Minister Sergei Lavrov said that Moscow "foresees and already senses" a new wave of accusations of "interference" in the American elections.
The Kremlin noted that Russia has never interfered in electoral processes in any country in the world.