Donald Trump vowed to temporarily ban immigration to the United States to combat the "invisible enemy" of the coronavirus, as the pandemic threatens to push the global economy into freefall. The president's late-night Tweet was scant on details but suggested a hardening of his anti-immigration crusade, a move likely to delight Trump's supporters ahead of November elections.

The threat came as the death toll from the virus surpassed 170,000 worldwide, sending economies into a tailspin as governments anxiously try to chart a path out of the crisis.

Freezes on whole sectors of commerce are playing out dramatically on oil markets, where shrinking energy demand and a supply glut have crashed prices.

In hard-hit Europe, some countries are cautiously creeping out from confinement to soften the economic costs, though large gatherings appear to be out of the question for the forseeable future.