Officials suspended action after three hours and 16 minutes following sustained heavy rain before deciding no further play was possible in New York.

Half of the 156-man field had yet to start their rounds, with the first two groups out completing just 11 holes.

With heavy rain forecast for Friday, the second round will not be completed before Saturday morning.

Should the weather force any more delays, play could extend into Monday, which is usually reserved in case an 18-hole play-off is required.

"The USGA is firm on this, that we will not determine a national champion until we play 72 holes," said Mike Davis, senior director of rules and competitions at the United States Golf Association.

"So if that takes us to Monday or Tuesday, whatever. We had to get in as many holes as we possibly could and we played more holes than we thought."

Graeme McDowell, coming off a top-five finish last week in Memphis, finished at one over after five.