Russian President Vladimir Putin said on Friday he had invited US leader Donald Trump to visit Moscow and was ready to travel to Washington for a new summit, as he praised their "useful" meetings.

Speaking after their Helsinki summit sparked a political crisis in the United States, Putin said the two leaders planned to meet on the sidelines of a summit in Argentina later this year and possibly at other venues.

"I am ready to go to Washington," Putin told reporters after a summit of the leaders of the BRICS group -- Brazil, Russia, India, China and South Africa -- in Johannesburg, adding that he had also invited Trump to visit Moscow.

"He has a desire to conduct meetings in the future and I am ready," he said, stressing however that conditions should be in place for such events to go ahead.

Putin said he and Trump planned to meet on the sidelines of a G-20 meeting in Buenos Aires starting late November and possibly other venues which he did not name.

"Life goes on and our contacts are continuing despite all the difficulties -- the difficulties in the US domestic political life," Putin said.

He said the two leaders needed to see each other face-to-face to discuss a host of international and bilateral issues.

"Contacts at the highest political level are needed," Putin said. "You cannot discuss everything by phone."

The Kremlin chief spoke after the US administration earlier this week delayed a second summit between Putin and Trump to next year under fire from critics at home.

The summit between the US and Russian leaders in the Finnish capital this month unleashed political turmoil in Washington, with some critics accusing the US president of betraying America's interests.

Trump faced intense criticism after the Helsinki news conference, during which he appeared to support Putin's "extremely strong and powerful" denial of subverting the 2016 US presidential election.