The US Open was washed out for the second day in a row on Wednesday, leaving organisers scrambling to clear a backlog and appease players who revolted against conditions on the court.

US Tennis Association (USTA) officials reluctantly cancelled all six men's single matches, including four fourth-round clashes originally scheduled for the previous day, after just 16 minutes of play in the day session.

They left open the possibility of playing the four women's quarter-finals in the evening session, but they too were cancelled because of persistent drizzle from the remnants of Tropical Storm Lee, just as the players were about to warm-up on court.

"It was definitely misting out there and with my luck I would have broke my neck and I was not up for that today," said Serena Williams.

Thousands of paying spectators retreated to the exit gates, leaving officials with another hefty refund bill and the possibility that the championship will be pushed to a third week for the fourth year in succession.

"This is one of the biggest events in tennis, a Grand Slam tournament event with huge revenues, so maybe they should consider a roof in future," said top seed Novak Djokovic, echoing sentiments that others have advocated for years.

Djokovic, whose quarter-final against his Serbian Davis Cup teammate Janko Tipsarevic was postponed before he even made it on court, said he supported the players who complained about being ordered to start playing when it was still sprinkling.

Rafa Nadal, Andy Murray and Andy Roddick confronted tournament organizers after their matches were halted, saying the conditions were already dangerous before they began.

"It was still raining when they called us on court. The rain never really stopped, the courts were not dry," said Nadal, who was trailing Gilles Muller 3-0 when play was stopped.

"I know the fans are there but the health of the players is important."

Roddick, who was leading fifth seed David Ferrer 3-1, also said the well-being of the players was paramount.

"I understand they need to put tennis on television, I understand the business side of it, but they need to make sure the players are safe," Roddick said.

The USTA defended their actions, saying they believed the courts were fit to play on but had agreed to take the players' concerns into account when they suspended play.

"Conditions may be not ideal, but still can be safe," the USTA said in a statement.

"However, if a player or players feel that conditions are unsafe, we listen to them, as we have always done, and the referee uses that information as part of his/her assessment on whether to continue or halt play."

The cancellations have left officials racing against time to finish the tournament by Sunday, and some of the men facing the daunting prospect of having to play four best-of-five set matches in as many days.

In each of the last three years, the men's final has been held over until the Monday because of rain delays, triggering an annual debate over why there is still no roofed court at the National Tennis Center.

The centre courts at both the Australian Open and Wimbledon have retractable roofs, while organisers of the French Open plan to cover up their main court by 2014.

However, the USTA has balked at the idea because of the enormous cost of covering Arthur Ashe Stadium, the largest tennis stadium in the world.

"I'd love to have a roof. Having said that, a roof on Arthur Ashe Stadium is technologically a challenge and financially its cost is prohibitive, upward of $200 million," said tournament director Jim Curley.

"Would I love to a have a roof? Sure, I'd love to have numerous roofs. Do I think it's gonna happen? I think it's a real challenge for a roof to be put on Ashe."