David Cameron has called on Britain's European partners to commit more aid to help famine-hit countries in the Horn of Africa.
Speaking after an hour-long meeting with members of the Somalian community in Birmingham today, the Prime Minister said the UK had shown "strong leadership" in its efforts to alleviate the crisis.
"Britain has spent £90 million - other countries are not doing as much and frankly, they need to do more," he said.
After thanking members of the local community for their personal efforts to help those affected by famine, Mr Cameron said: "Britain is showing very strong leadership.
"We have done the most and my aid minister has been to the Horn of Africa to see for himself what needs to be done.
"We have three-and-a-half million people affected by famine and two million of those are not getting any help.
"It's time for other European countries to start doing what Britain is doing, and to give more to make sure the aid gets through and we save lives."
Labour leader Ed Miliband paid a visit to the Disasters Emergency Committee's offices in London as the organisation announced that its East Africa Crisis Appeal had raised £27 million for the drought-stricken countries in the Horn of Africa.
Mr Miliband hailed the organisation for its "amazing job".
He said: "The British public are to be thanked for £27 million being donated in the last two weeks, but there is a huge humanitarian emergency in Somalia and Ethiopia. That's why we've got to get European governments to start stumping up the money, because so far they haven't.
"The British Government is doing a good job on this, but the other European governments, the United States, need to do a far better job, because half a billion pounds is needed."
He added: "We've got 10 million people at the moment who are in very difficult circumstances, facing the terrible drought, and we need those governments as well as the public to now show that they are going to give the money that is required."
Famine has been officially declared in two regions of Somalia following the worst drought in 60 years, affecting more than 10 million people in Ethiopia, Kenya, and Republic of South Sudan.
During his visit to a community centre in the Camp Hill area of Birmingham, Mr Cameron acknowledged that long-term solutions were required in Somalia, but stressed that more aid was urgently needed.
The Prime Minister added: "Of course, in the longer term there is a huge amount more to do to strengthen government in Somalia, to build the resilience of Somalia, but right now people are dying.
"Their lives could be saved by some aid. Britain is playing its part - others have got to play their part too.
"We have given a large amount of money - £90 million, more than other countries. It's time, frankly, for other countries to step up to the plate and recognise what's happening."
Mr Miliband was given a tour of the DEC's offices in Euston by chairman Clive Jones and chief executive Brendan Gormley.
He took time to view the response of the DEC aid agencies on an interactive map of East Africa before meeting staff and making a donation via text message on his phone.
Mr Miliband said the problem was a "real emergency", with hundreds of thousands of people flowing across borders, facing extreme drought and "at risk of death", adding: "We need to act."
Mr Gormley said the British public had been "stunningly generous", but added: "The gap between what is needed and what can be paid for is still sadly enormous."
He said the money donated would go to the "absolute basics of life" including clean water, food and shelter.
The need, he said, was across the whole of East Africa following the widespread crop failure, with families now on the move towards Mogadishu, Somalia's battle-worn capital.
He said: "The phone-hacking story, obviously, for the people who were hacked was a travesty and it was dreadful, but in the balance on things East Africa now should be at the top of every news agenda."
Of Mr Miliband's visit, he said: "It's terribly important for us to reassure the British public that we are the cost-effective way to give. Having the leader of the Opposition here endorsing that should reassure people that this money will be spent quickly, wisely and well."
Among those present during Mr Cameron's visit was the UK director of Islamic Relief, Jehangir Malik, who said the scale of the famine was increasing daily.
"We have got 30% malnutrition rates in some of the areas that we have witnessed and that we work in," the charity worker told the Press Association.
Mr Malik, who praised the British public for its generous response to previous humanitarian disasters, said: "We have got a phenomenal need on the ground and too little aid coming in.
"The scale of the disaster is such that we need the British public to dig deep."
Unicef was preparing today to airlift another 105 tonnes of food and medical supplies to the region, and a shipment will leave for the Horn of Africa in the next few days. So far 1,300 tonnes of emergency supplies have been sent to the area.
The charity's UK executive director David Bull said: "We have stepped up our response even more as the death rate among severely malnourished children under the age of five in Lower Shabelle in south Somalia has climbed dramatically. They are now dying at a rate of more than 250 per day - that's one child every six minutes. This is totally unacceptable and we must all act now to help save lives."
Unicef estimates it will need £62.8 million over the next six months to help children affected by the drought.
The Secretary of State for International Development, Andrew Mitchell, was also in attendance at the meeting in Birmingham.
Commenting on his recent visit to Kenya, Mr Mitchell said: "The women I met at Dadaab a few days ago, their feet bloodied by weeks of walking to reach this refuge, told me harrowing stories of their journeys.
"Some had been robbed, others encountered violence. Some had even lost their children to hunger on the way.
"I was horrified by what I saw and was eager to talk to the Somali community in Birmingham today about what Britain is doing to help."