Washington (CNN) President Donald Trump said Tuesday that Russia had "no impact on our votes" in the 2016 presidential contest but vowed to combat any attempts to meddle in the 2018 midterms.

It was Trump's most forceful attempt to date at dissuading Russia from continuing its election interference efforts, though he again suggested that other countries may have been involved and continued to insist the final results were not affected by Moscow.

The President said it was important to guard against meddling efforts during the midterm contests.

"I think you have to be really watching very closely. We won't allow that to happen," Trump said. "We're doing a very, very deep study and we're coming out with, I think, some very strong suggestions on the '18 election."

Read More