The White House has said it will send out special teams to hot spots around the United States to combat the highly contagious Delta coronavirus variant amid rising case counts in parts of the country where vaccination rates remain low, Reuters reports.

The speedy US vaccination campaign has dramatically reduced Covid-19 cases among residents. The peak seven-day-average of more than 250,000 cases per day in January fell to around 11,000 in mid-June.

But daily cases have since leveled out and in the past week rose about 10 per cent to about 12,500, driven by case increases in the Midwest and Southeast where vaccination rates are low and the highly contagious Delta variant, first found in India earlier this year, is spreading.