Joe Biden warned the worst of the coronavirus pandemic is still to come, as the number of American deaths due to Covid-19 surpassed the country's troop fatalities in World War II.Biden was expected Thursday to unveil his administration's plans to tackle the coronavirus crisis, as he starts his first full day in the White House with America confronting a slew of challenges.Covid-19 cases have surged past 96 million worldwide, fuelled by the emergence of the new strain of the killer virus, including one that was first detected in Britain, and has now spread to over 60 nations, the World Health Organization has said.America remains the worst-hit country, with around a fifth of the two million global coronavirus deaths, and Joe Biden has made.