Matt Giteau has described Argentina as "incredibly dangerous" ahead of Australia's Rugby World Cup semi-final against the Pumas at Twickenham.

Argentina beat Six Nations champions Ireland to progress to the last four, while the Wallabies needed a last-minute penalty to defeat Scotland.

The 33-year-old, who picked up his 100th cap in the quarter-final win, told reporters: "Argentina are very good at every World Cup. Whatever they do, they always seem to peak in these tournaments. They're incredibly dangerous.

"We've seen what they were able to do to Ireland and how far they pushed New Zealand in the first game. Every round they've been really good. They've blown teams away quite easily."

Australia are looking to win the tournament for the third time, while Argentina have never been past the semi-finals.