The health secretary Jeremy Hunt has pledged much faster diagnosis times for people with suspected dementia and says he wants Britain to be a leader in both diagnosis and the search for a cure.

Those who see their doctor with concerns about their memory and thought processes will by March be diagnosed within six weeks rather than six months, as is currently the case in some places, said Hunt. Only half of those with dementia now have a diagnosis at all – a figure he wants to rise to 66%.

At the moment, the wait for a diagnosis is no more than six weeks in about 75% of the country, but there are areas where it can be many months. Some doctors feel a diagnosis is not very helpful, because there are few treatments for the condition and the drugs that exist do not help everyone.

But, said Hunt at an international summit in Paris, the long uncertainty caused patients and their families stress and anxiety. Knowing the truth within six weeks would enable people to get access to drugs which can sometimes delay the progression of the disease. It would also enable families to plan for the future.

“How we respond to dementia is the litmus test of whether we can face up to the challenge of an ageing population, and do so in a way which allows compassion and dignity.

“Dementia can be a horrific and heartbreaking disease, but it is my mission as health secretary to make this country the best place in the world to get a dementia diagnosis, as well as a global leader in the fight to find a cure,” said Hunt in an interview with the Daily Telegraph.

One in three people will develop dementia in later life. In December, the government convened a G8 dementia summit in London, which concluded with a pledge to find a cure or treatment by 2025 – which many would think an ambitious goal. The UK promised to double its research funding to £132m by that year.

In Paris, the health secretary also said that Marks & Spencer, Argos, Homebase and Lloyds Banking Group will train more than 120,000 staff to help and support customers with dementia.

David Cameron will on Friday announce a World Dementia Council headed by a World Dementia Envoy. Dr Dennis Gillings, an expert in clinical research trials, is to stimulate research.

Labour said the prime minister was right to focus on dementia, but called for him to do more for those afflicted with the disease right now.

“£2.7bn has been cut from council care budgets under this government, hitting the quality of life of hundred of thousands of people with dementia and their families. This isn’t good for them, and is a false economy as an increasing number of elderly people with dementia are ending up in hospitals or care homes when they don’t need to,” said Liz Kendall MP, Labour’s shadow minister for Care and Older People.