(REUTERS) - Coronavirus cases more than doubled in 14 US states in the month of June, including California, Florida and Texas, a Reuters analysis on Tuesday (June 30) showed.

Arizona recorded the biggest jump in cases for the month at 294 per cent, followed by South Carolina at 200 per cent and Arkansas at 179 per cent.

Cases also more than doubled in Alabama, Alaska, Idaho, Nevada, North Carolina, Oklahoma, Oregon and Utah.

Nationally cases rose by at least 46 per cent and deaths increased by 21 per cent. A few states have yet to report cases on Tuesday.

While much of the world appears over the worst of the pandemic, the United States and a few other countries are still seeing huge daily spikes.

In the six months since the World Health Organisation (WHO) first reported a cluster of mysterious pneumonia cases in Wuhan, China, more than 500,000 people have died from the coronavirus, including over 126,000 Americans.

A strong national response, stringent lockdowns and mandatory mask wearing in public helped bring the pandemic under control in much of Asia and Europe. In the US, wearing masks has become a divisive political issue and many states began reopening businesses without having met government health benchmarks for doing so safely.

In the past week, 21 US states reported rates of people testing positive for the virus above the 5 per cent level that the WHO has flagged as concerning. Arizona has the highest rate in the country at 24 per cent.

Cases increased by less than 10 per cent in June in just four states - New York, Massachusetts, Connecticut and New Jersey.

New York, once the epicentre of the US epidemic, saw cases rise by about 6 per cent in June - the lowest rate in the country - after strict lockdown and social distancing measures were put in place to help bring the disease under control.