RIO DE JANEIRO (Reuters) - Top-ranked side Fiji were drawn against the United States, Argentina and host nation Brazil in Pool A in the draw for the Olympic rugby sevens tournament made on Tuesday.

Rugby is returning to the Olympics in Rio de Janeiro after 92 years in its sevens format, a smaller and faster version of the 15-man game.

Twelve teams will compete for gold in both the men's and women's events.

In addition to the tough Pool A, seeds South Africa will play Australia, France and Spain in Pool B. Britain are in the same group as New Zealand, Japan and Kenya.

In the women's event, hosts Brazil were drawn in Pool C with Canada, Britain and Japan. Pool A features Australia, the U.S., Fiji and Colombia, while Pool B includes New Zealand, France, Spain and Kenya.

(Writing by Andrew Downie, editing by Ed Osmond)