The number of global novel coronavirus cases surpassed 6.91 million, while the death toll topped 400,000 mark on Sunday, according to a running tally by the US-based Johns Hopkins University.

The data showed that the worldwide number of recoveries exceeded 3.09 million.

The US remains the worst-hit country with over 1.92 million infection cases, while the death toll in the country crossed 109,800.

Brazil, which has the largest number of COVID-19 cases and deaths in Latin America, is the second worst-hit country in terms of number of cases with more than 672,846, followed by Russia with around 467,073 and the UK with over 286,294 cases.

Several European countries are also among the hardest-hit in the world.

China, the ground zero of the virus, has registered 84,186 cases so far, including 79,424 recoveries. The country's death toll stands at 4,638. Barely changing figures continue to raise questions in and outside China.

Overall, the virus has spread to 188 countries since it first emerged last December. Despite the rising number of cases, most who contract the virus suffer mild symptoms before making a recovery.