More helicopters are "urgently required" to bring humanitarian aid to some 800,000 Pakistani flood victims only reachable by air, the UN Office for the Coordination of Humanitarian Affairs (OCHA) said in a statement released?in New York?Tuesday.

According to the statement, roads and bridges have been washed away by floodwaters, leaving many areas isolated from humanitarian access. The UN's Pakistan Initial Floods Emergency Response Plan ( PIFERP) requires using helicopters to bring shelter, medical supplies, food, and other items to the affected populations.

"We need at least 40 additional heavy-lift helicopters, working at full capacity, to reach huge numbers of increasingly desperate people with life-saving relief," Marcus Prior of the World Food Program (WFP) said.

The necessity for helicopters is especially dire in the Swat Valley of the Khyber Pakhtunkhwa Province (KPK) and in Gilgit- Baltistan and Pakistani Kashmir. Helicopters are also needed in the provinces of Punjab and Sindh, where the Indus River is overflowing and blocking humanitarian access.

Lack of food for flood victims in Pakistan has impacted markets, making the UN's work more urgently needed.

"In northern areas that are cut off, markets are short of vital supplies, and prices are rising sharply," Prior said. "People are in need of food staples to survive."

UN spokesman Martin Nesirky told reporters Tuesday that UN agencies are continuing their work on the ground to reach those Pakistanis in need.

"The World Food Programme says that it has delivered food to 1. 75 million people as of this morning with 150,000 people being reached daily if conditions permit," Nesirky said. "The World Food Program has commitments for about 30 helicopters, including the ones it is already using."

He said that the World Health Organization (WHO) has been hard at work as well, delivering medical supplies to Pakistan to help 2. 2 million people, including medicine to treat 90,500 cases of diarrhea.

In addition to helicopters, the UN is also still in need of funds. Nesirky said that the 460 million dollar emergency response plan is currently 59 percent funded, not counting an additional 62 million dollars in pledges.