The global response to the horrific typhoon disaster in the Philippines gathered pace Tuesday, with the launch of a $300 million appeal by the United Nations as countries and companies swung into action.

UN humanitarian chief Valerie Amos, in Manila, praised the international community's response to Super Typhoon Haiyan but insisted much more needed to be done to help people hit by a catastrophe her organisation fears may have already killed 10,000.

"We've just launched an action plan focusing on the areas of food, health, sanitation, shelter, debris removal and also protection of the most vulnerable with the government and I very much hope our donors will be generous," she told reporters.

"That plan is for $301 million dollars," Amos said, adding it was over and above other sums already pledged and did not include $25 million that the United Nations' central emergency response fund has made available.

"At this point in time it's extremely difficult even to get a sense of what the immediate needs are because it is very difficult to get to some of the areas affected."

The UN estimates that more than 11.3 million Filipinos have been affected, with 673,000 made homeless, since Haiyan -- one of the most powerful typhoons ever -- smashed into the nation's central islands on Friday.

The United States said the aircraft carrier USS George Washington, with 5,000 sailors and more than 80 aircraft aboard, was heading to the Philippines to join 180 US Marines already on the ground.

Britain boosted its aid to 10 million pounds ($15.8 million) and sent a destroyer from Singapore, as well as a transport plane.

Other significant contributions included:

-- The United Arab Emirates, which has a large Filipino expatriate community, pledged $10 million.

-- The Australian government pledged Aus$10 million ($9.38 million), with a team of medics set to leave Wednesday.

-- Tokyo said it would supply $10 million in grants to provide evacuees with emergency shelters and other assistance. It will also send a 40-strong military detachment.

-- Indonesia pledged $2 million in cash and emergency supplies, with a Hercules aircraft set to depart Wednesday carrying food, medicines, water filters and generators.

-- China, where the typhoon killed several people, is to give $100,000 towards the aid effort. The state-run Global Times said a territorial row with the Philippines should not affect such decisions.

-- Taiwan sent two C-130 Hercules transport aircraft carrying relief goods and pledged $200,000 in cash despite its diplomatic row with Manila triggered by the fatal shooting of a fisherman in May by a Filipino coastguard.

-- Vietnam, itself faced with mass evacuations as a weakened Haiyan swung through its territory Monday, has offered aid worth $100,000.

-- South Korea approved $5 million in emergency aid and dispatched a 40-member team including medical personnel and rescuers to Tacloban.

-- Samsung Group donated $1 million dollars through international aid groups and HSBC said it was donating the same sum.

-- The European Commission said it would give 13 million euros ($17 million) while India said it was sending an aircraft with 15 tonnes of relief materials.

-- Germany's embassy in Manila said an initial shipment of 23 tonnes of aid was being flown in and German rescue teams were already at work.

-- New Zealand increased its humanitarian relief to NZ$2.15 million ($1.78 million), Canada has promised up to $5 million to aid organisations, Malaysia readied a relief crew and Singapore offered cash aid.

-- UN children's fund UNICEF sent a cargo plane carrying 60 tonnes of aid including shelters and medical kits while refugee agency UNHCR organised an airlift.

-- The ASEAN Coordinating Centre for Humanitarian Assistance on Disaster Management will send an initial $500,000 in aid from Subang in Malaysia.

-- Medecins Sans Frontieres (Doctors Without Borders) said it was sending 329 tonnes of medical and relief items which will arrive in Cebu within the next few days in four cargo planes.