WASHINGTON (AP) - U.S. and Chinese negotiators start two days of high-level talks Wednesday aimed at settling a six-month trade war that has weakened both sides, shaken financial markets and clouded the outlook for the global economy.

Yet the odds seem stacked against any substantive resolution this week to the standoff between the world's two biggest economies. Perhaps the best that might be hoped for, analysts say, is for the two sides to agree to keep talking. The differences between Beijing and Washington are vast.

The United States is essentially demanding that China downsize its aspiration to become a supreme world leader in such fields as robotics and electric cars. "A comprehensive deal that fundamentally changes their system - I don't think that's possible," said Christopher Adams, a former U.S. trade official.