President stated that the " exhaustive investigation " will supervise former FBI Director Robert Mueller as newly appointed " " will prove the lack of links between his campaign and Russia .
As I have said many times, a thorough investigation will confirm what we already know: there was no collusion between my campaign and any foreign agency, "Trump said in a statement.
The Justice Department appointed Mueller as "special prosecutor" to oversee the FBI's investigation into Russia's interference in the 2016 election, including its alleged ties to the Trump campaign.
My decision is not a finding that crimes have been committed or that an accusation is warranted. I have not reached such a determination, "Deputy Prosecutor Rod Rosenstein said in a statement announcing the appointment of Mueller.
"What I have determined," he said, "is that, on the basis of unique circumstances, the public interest requires that this investigation be carried out under the authority of a person exercising some degree of independence from the normal chain of command"
The deputy prosecutor insisted that "a special prosecutor is necessary for the American people to have complete confidence in the result" of the investigation.
The new special prosecutor headed the Federal Bureau of Investigation (FBI) for twelve years under the presidencies of Republican George W. Bush and Democrat Barack Obama, until his retirement in 2013.
The Democratic opposition has been calling for the appointment of an independent special prosecutor to investigate possible links between Trump's campaign and Russia, but most Republicans have hitherto been opposed to it.