A travel warning to American citizens in Zimbabwe urging them to leave the African country has been issued by the US government.

The US State Department says that Zimbabwe's current political, economic and humanitarian crises have serious implications for security and it recommends that people should consider leaving.

The warning says: “All US citizens in Zimbabwe are urged to take those measures they deem appropriate to ensure their well being, including consideration of departure.”

The Zimbabwe government's appropriation of land from farmers and suppression of political opposition has helped to fuel a crisis, raising the possibility of violent protest.