Chile has turned all of its Pacific Ocean territorial waters into a whale sanctuary.

President Michelle Bachelet on Wednesday signed into law a measure that bans all whale hunting off Chile's 5500-kilometre coast.

The law bans whale hunting both for commercial and scientific purposes.

Bachelet calls the law "a big step ahead in the protection of nature and a major legacy to future generartions".

Chile has not hunted whales for about three decades, but the Government sought the law to emphasise its decision to protect whales in its waters.

Argentina, Brazil, Costa Rica, Mexico and Panama already ban whale hunting.

A whale sanctuary exists in Antarctica.

AP