U.S. stock index futures were flat on Wednesday as investors focused on potential developments on the trade front after a strong start to the week, when soft inflation numbers and Washington's trade truce with China boosted sentiment.

U.S. stock futures point to a flat open after a generally positive start to the week that has seen the broad S&P 500 index turn positive on the year.

U.S. stock index futures were flat on Wednesday, following a strong start to the week when a soft inflation reading and a U.S.-China trade truce lifted sentiment, with focus