Gordon Brown has urged people with swine flu symptoms to seek advice as he offered reassurance that Britain is well-placed to deal with the outbreak.
On a visit to an NHS Direct call centre in Beckenham, south east London, the Prime Minister said the advice line was coping well with demand.
He said the Government was increasing the number of face masks available to the NHS and looking at different vaccines, while stressing that the Tamiflu anti-viral drug would deal with the bug.
He said there are still only eight confirmed cases of swine flu in Britain, although an NHS worker is expected to find out if he is the country's first case of human-to-human transfer.
"There will be more cases," Mr Brown cautioned. "This is happening in every country of the world, but we are better prepared.
"If people have the symptoms they should ask for advice as quickly as possible. And we are finding with NHS Direct that they can both reassure people and give people advice about where to go.
"This is a system that's working, it's calm, it's ordered, it's giving people the right information."
Mr Brown said all the cases in the UK had come from Mexico and were mild.
"We know that this is happening around the world and we know also that we have preparations in place so that people can get the Tamiflu anti-viral drug and can be treated if they get the disease," he said.
"As long as people can seek the information quickly and get the answers and then take the action that is necessary, using NHS Direct, using the local GP, using the internet service that's also available on NHS Direct, then we can help people get the information so that action can be taken quickly enough. We are doing everything we can and will continue to do everything we can to contain this."
