Oil prices tumbled Monday after US President Donald Trump said he was preparing for new talks with Iran aimed at ending the war in the Middle East, which also helped lift stocks.
Crude futures slid more than six percent, even though Iran denied that any negotiations were taking place.
The yen meanwhile surged against the dollar after US and Japanese authorities confirmed Monday that they had bought Japan's currency on the open markets after months of weakness.
But while a weaker yen helps big exporters like Sony or Toyota, it also inflates import costs for Japan, and the main Japanese stock index fell nearly one percent on Monday.
Elsewhere on Asian markets, technology companies again saw heavy losses as traders worry about whether massive investments in artificial intelligence will deliver long-lasting profits.
