The Dow Jones Industrial Average ended down 178 points, or 1%, to 17,966.07. The Standard & Poor’s 500 and Nasdaq indexes, meanwhile, both dropped 0.7% to 2,108.58 and 5,122.41, respectively.

Greece Prime Minister Alexis Tsipras is set to resume talks with his country’s creditors once again Wednesday. That comes after a meeting with eurozone finance ministers earlier in the day failed to provide any clarity on the path forward. Greece’s creditors have taken a hard line with the indebted nation despite its acquiescence to a number of austerity measures, taking many investors by surprise, Paul Hickey at Bespoke Investment Group told USA Today.

Since there’s a slight lull in the earnings calendar, there can be little doubt Greece is the key linchpin that’s causing uncertainty in the markets. “There has been some nervousness that the Greece situation may not get resolved soon,” Bill Schultz, chief investment officer at McQueen, Ball & Associates, told Bloomberg.

Meanwhile, overseas markets have been mixed. Japanese stocks rose, helping the Nikkei 225 hit an 18-year high. European stocks were mostly lower: Germany’s was DAX down by 0.6%; France’s CAC 40 fell 0.3%; Britain’s FTSE 100 bucked the trend and gained 0.2%.