Although Washington and Beijing labelled their two-day talks last week as "productive" and "constructive," a deal appeared elusive after Chinese officials unexpectedly cancelled a visit to US farms on Friday.
Focus now turns to high-level talks planned for October.
MSCI's index for Latin American stocks fell 0.6%, led by Brazil's Bovespa, dragged down mainly by financial companies.
Shares of Embraer fell nearly 2% after a Reuters report said EU antitrust regulators are set to open a full-scale investigation of Boeing's $4.75 billion bid for a controlling stake in Brazilian planemaker.
The real slid 0.6%, on course to end the month lower. Data showed Latin America's largest economy posted a current account deficit of $4.27 billion in August, slightly wider than the $3.96 billion shortfall forecast.
Also pressuring currencies in the region was a firmer dollar, which gained after the euro fell following poor manufacturing activity readings in the euro zone showing contraction at its steepest rate since late 2012 as demand sank.