Investors are treading cautiously as talks between Washington and Tehran over the weekend were clouded by a renewed threat from US President Donald Trump to strike Iran.

Investors are treading cautiously as talks between Washington and Tehran over the weekend were clouded by a renewed threat from US President Donald Trump to strike Iran.

The Australian sharemarket is set for an unsteady start to the week as US President Donald Trump continued to threaten Iran even as talks began in Switzerland between his vice…