Venus Williams has described her Olympic doubles win with sister Serena as an "incredible" achievement after their triumph at Wimbledon on Sunday.

The straight-sets victory over Czechs Andrea Hlavackova and Lucie Hradecka saw the Americans claim gold for a record third time in the event following successes at Sydney in 2000 and Beijing in 2008.

"It's incredible. Coming off Serena's [singles] victory I think most of all we are happy to add to our country's medal count and be a part of it," said Venus.

"I would say this is more special than Wimbledon. I'm amazed she won the singles and our main goal was to win the doubles, so we got both and it's amazing."

The elder of the Williams sisters also revealed that they expect to defend their title at the 2016 Games in Rio de Janeiro.

"We're definitely planning on Rio," she added. "We're going out with a bang in Rio. Hopefully we will make it four, you never know."

Both Venus and Serena now have more Olympic tennis medals than any other players in the history of the Games with four each.