The CIA has concluded that Russia intervened in the 2016 election to help President-elect Donald Trump win the White House, and not just to undermine confidence in the U.S. electoral system, a senior U.S. official said on Friday.

U.S. intelligence agencies have assessed that as the 2016 presidential campaign drew on, Russian government officials devoted increasing attention to assisting Donald Trump's effort to win the election, the U.S. official familiar with the finding told Reuters on Friday night on condition of anonymity.

Citing U.S. officials briefed on the matter, the Washington Post reported on Friday that intelligence agencies had identified individuals with connections to the Russian government who provided thousands of hacked emails from the Democratic National Committee and others, including the chairman of Hillary Clinton's presidential campaign, to WikiLeaks.

Whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States.

"Nothing was more to be desired than that every practicable obstacle should be opposed to cabal, intrigue, and corruption. These most deadly adversaries of republican government might naturally have been expected to make their approaches from more than one querter, but chiefly from the desire in foreign powers to gain an improper ascendant in our councils.

How could they better gratify this, than by raising a creature of their own to the chief magistracy of the Union? But the convention have guarded against all danger of this sort, with the most provident and judicious attention.

They have not made the appointment of the President to depend on any preexisting bodies of men, who might be tampered with beforehand to prostitute their votes; but they have referred it in the first instance to an immediate act of the people of America, to be exerted in the choice of persons for the temporary and sole purpose of making the appointment.

And they have excluded from eligibility to this trust, all those who from situation might be suspected of too great devotion to the President in office. No senator, representative, or other person holding a place of trust or profit under the United States, can be of the numbers of the electors.

Thus without corrupting the body of the people, the immediate agents in the election will at least enter upon the task free from any sinister bias. Their transient existence, and their detached situation, already taken notice of, afford a satisfactory prospect of their continuing so, to the conclusion of it.

The business of corruption, when it is to embrace so considerable a number of men, requires time as well as means. Nor would it be found easy suddenly to embark them, dispersed as they would be over thirteen (now 50) States, in any combinations founded upon motives, which though they could not properly be denominated corrupt, might yet be of a nature to mislead them from their duty."