U.S. President Donald Trump has said on his Twitter microblog that Ukraine attempted to sabotage his [2016] election campaign in favor of his rival Hillary Clinton.

"Ukrainian efforts to sabotage Trump campaign - "quietly working to boost Clinton." So where is the investigation A.G. @seanhannity," Trump tweeted on Tuesday.

As earlier reported, Trump won the 2016 presidential campaign, garnering 306 electoral votes. His inauguration took place on January 22, 2017.

Trump's nearest competitor in the race from the Democratic Party was Hillary Clinton.