The United Nations on Wednesday launched an appeal for 460 million U.S. dollars for disaster relief efforts in flood-stricken Pakistan.

The UN Office for the Coordination of Humanitarian Affairs ( OCHA) is seeking the funds to support Pakistan during the duration of the immediate relief period, said UN humanitarian chief John Holmes.

Holmes said that under the plan, UN agencies and other organizations would supplement Pakistan's efforts in major priority areas, including food, clean drinking water, and medical supplies.

The main elements of the appeal include 105 million U.S. dollars which is required to provide tents or plastic sheeting, as well as for basic household goods, for an initial target of over 2 million people.

With a high risk of a food crisis, food assistance is necessary for up to 6 million people across the country, requiring 150.5 million U.S. dollars.

Clean water is expected to be provided to approximately six million people who face an increasing risk of waterborne diseases, which will require 110.5 million U.S. dollars.

Some 56.2 million U.S. dollars is for emergency health care, while 14.2 million U.S. dollars is needed for proper nutrition for children under aged five, as well as for pregnant women or lactating women.

The plan will be revised within 30 days in order to reflect " assessed needs as the situation evolves," particularly examining strategies for assisting people with early recovery from floods, specifically in the key agricultural area, Holmes said.

Unless "aid activities continue to be rapidly scaled up" to reach those displaced and without immediate access to basic necessities, additional loss of human lives and further suffering will occur,Holmes warned.

OCHA said that donors have already committed or contributed 47. 8 million U.S. dollars to the response activities of the UN and its partners.

An additional 99.5 million U.S. dollars has been pledged, OCHA noted, while also stressing that "over 300 million U.S. dollars is still urgently needed."

The "emergency is still evolving," with continued rainfall and monsoon season still lingering as more areas are at high risk of flooding and hundreds of thousands of people on the move, OCHA said.

The government of Pakistan estimated that more than 14 million people have now been affected by the floods, which have devastated large parts of the country from north to south.

OCHA said Pakistan's "worst monsoon-related floods in living memory" have affected more than 14 million people and at least six or seven million require immediate humanitarian assistance.

More than 1,200 people have died and at least 288,000 homes have been damaged or destroyed in the flooding, the agency said.