The joint mission was to be in Fiji from 19 January to 23 January, as part of international efforts to help Fiji return to democracy following the 2006 military coup.
In a statement, the UN says at the request of the Interim Government and due to the gravity of the humanitarian situation caused by the floods, the UN-Commonwealth Technical Team has been delayed.
It says the UN and the Commonwealth are consulting on new dates for the visit, which should take place as soon as feasible.
The United Nations says it is deeply concerned at the loss of life, displacement and serious damage to property caused by the floods and expressed its condolences to the government and people of Fiji.
Cost of cleaning rises
The cost of the flooding in Fiji continues to rise as a clean-up begins.
Eleven people have died and 300 businesses are ruined.
Some estimates of damage in Nadi alone are $200 million and there are calls to bulldoze the town and start again.
There are also calls to relocate some villages to higher ground.
But the mayor of Nadi says people must wait to see what government and international assistance will come before considering such drastic options.
The sugar cane industry has been decimated.
Thousands of acres of cane have been destroyed and the Cane Growers Association says the industry will take years to recover.
The industry is second only to tourism as Fiji's biggest industry. It brings in more than $US250 million annually, Most of the three million tonnes crushed annually is sold to markets in the European Union.