Apparent progress follows multiple rounds of discussions
France's CAC 40 and Germany's DAX were up 0.4% and 1.1%, respectively
The details of the U.S.-China pact are still sketchy
The Dow Jones Industrial Average climbed 0.8%
US stocks had broadly gained Tuesday as investors waded into the market
The U.S. Cabinet secretary noted that negotiating with China is likely to be "a slog