The UK is to give another £5m to the relief effort in Nepal, bringing Britain's contribution to £15m.
More trauma medics and heavy lifting equipment to help move supplies at Kathmandu airport will be included in the aid package, the government said.
More than 5,000 people are now known to have died in Saturday's earthquake.
The latest pledge, which comes after leading UK aid agencies launched a TV appeal for donations, means Britain now tops the league of financial donors.
Many other countries have also sent emergency aid, including India, which has 13 of its military helicopters scouring the most remote areas of the disaster zone.
BBC world affairs correspondent Naomi Grimley said as the dust settled, it was becoming clearer what was needed on the front line of the rescue and relief effort.
Two of the biggest problems were the lack of doctors, and congestion at Kathmandu airport, she said.
The UK's additional £5m aid package will include:
• A 30-strong medical team carrying eight tonnes of equipment, including medical supplies, bandages, a generator and tents
• Airfield handling equipment, including two forklift trucks to help with moving aid supplies off aircraft
• An agreement to fund humanitarian experts in water, health and sanitation to help co-ordinate the relief effort
Announcing the additional aid, International Development Secretary Justine Greening said the UK was playing a leading role in response to the Nepal earthquake.
Nepal has declared three days of national mourning for the victims of the 7.8-magnitude earthquake and subsequent aftershocks. Officials say the death toll has now passed 5,000, but could reach 10,000, with at least 8,000 people injured.
Among the dead are 18 climbers who were at Mount Everest base camp when it was hit by an avalanche triggered by the quake.
The Foreign Office says it is is investigating reports a Briton living overseas was killed in the earthquake.
Foreign Secretary Philip Hammond said at least 500 Britons had been accounted for but staff were contacting tour operators and hospitals to trace others.
He is expected to chair a meeting of the Cobra emergency committee on Wednesday.
Mr Hammond said the Foreign Office had estimated there were between 500 to 1,000 British nationals in Nepal but there was "no single co-ordinated list".
Officials had assisted more than 250 British nationals and 583 "either have left the country or are not in the country or are accounted for and safe in the country", he said.
The BBC is aware of about 30 British or Irish families who are still waiting to hear from relatives.
One mother told the BBC of her relief after her son contacted her.
Sue Gerhardt from Oxford, whose son Laurie, 24, was trekking in Nepal when the earthquake hit, said she felt "dizzy" when she received a phone call from him saying he was safe.
She said: "It was a very short conversation and that is really all I know - that he's there.
"They have been told it is far too dangerous to travel because of the aftershocks and the condition of the roads and so on."
The televised appeal was launched on Tuesday by the Disasters Emergency Committee, an umbrella organisation which brings together 13 UK aid charities to deal with international crises.
Actress Joanna Lumley, who has campaigned for the rights of the Nepalese British Army Gurkhas, presented appeals aired on the BBC, ITV, Channel 4, Channel 5 and Sky. A website and donation line was launched earlier.
The UK government has promised to match the first £5m of public donations to the DEC appeal.
Downing Street has already given £5m to help people affected by the earthquake. It said it had released £3m to address immediate needs and that £2m would be given to the Red Cross.
A team of more than 60 search and rescue responders and medical experts deployed by the Department for International Development are in Nepal.
An RAF plane carrying aid supplies and Army troops has also been sent to the country.