Prime Minister John Key says the Government is committed to restoring the beaches and marine environment affected by the grounding of the container ship off the coast of Tauranga.
Mr Key visited Maketu Peninsula on Wednesday which has been affected by oil that has leaked from the Rena wedged on the Astrolabe Reef, 12 nautical miles offshore.
Mr Key says insurance cover for the Greek-owned ship is capped and the rest of the salvage and clean-up costs will have to be borne by the New Zealand Government and unfortunately, there is a significant amount of work ahead.
But Labour Party leader Phil Goff says the response to the country's biggest environmental marine disaster to date has been too slow.
Mr Goff visited Tauranga on Wednesday and was briefed by Maritime New Zealand on the ship's grounding and oil spill.
He says more should have been done to get oil off the Rena before bad weather made it impossible and local people are angry and frustrated by what has happened.
Maritime New Zealand says its Wildlife Response Centre in Tauranga has 41 birds in its care - a mixture of shags, petrels, dotterels and little blue penguins.
Three seals are at the facility, with two more on their way on Wednesday night.
Some 200 dead birds have so far been collected.