The number of new coronavirus cases in the US topped 50,000 for the first time on Wednesday, led by record increases in California, Texas and Arizona that have emerged as some of the new hot spots for the virus.

A further 52,982 people tested positive over the past 24 hours, according to data compiled on Wednesday by Covid Tracking Project, up from 44,358 on Tuesday. The daily increase surpassed the previous record on June 26 by just over 8,600.

California's health department said earlier on Wednesday 9,740 people tested positive for Covid-19 over the past day, a record increase. Only New York, the early hot spot for the virus in the US, has experienced single-day increases bigger than this, according to Financial Times analysis of Covid Tracking Project data. Just over 87,000 tests were conducted in the state, a drop from back-to-back days of more than 105,000.