Thousands of US troops have arrived in Haiti in an effort to improve security and help distribute the humanitarian aid that is continuing to arrive there.

The UN Security Council is expected to approve the deployment of a further 3,500 UN peacekeeping soldiers following a request from Ban Ki-moon, the organisation's secretary-general.

However, some critics say medical equipment, nurses and doctors should be given priority access to the country if aid efforts for those most in need are to succeed.

Sebastian Walker reports from Port-au-Prince.