By David Lawder, Greta Rosen Fondahn and Maria Martinez STOCKHOLM (Reuters) -U.S. and Chinese officials agreed to seek an extension of their 90-day tariff truce on Tuesday, following two days of what both sides described as constructive talks in Stockholm aimed at defusing an escalating trade war between the world's two biggest economies that threatens global growth.

The U.S. and China had agreed to pause most of the sky-high tariffs on each others' goods amid trade negotiations – but that pause is set to expire in August.