President Obama was due to host a lavish dinner for Saudi Arabia’s recuperating King Abdullah in New York today — but postponed their meeting following the Arizona tragedy.

Obama was to dine with the king, who’s recovering from back surgery, and 20 others at The Plaza hotel’s Oak Room early this evening. Sources tell us the Plaza was due to be locked down for five hours for Obama’s dinner with Abdullah, whose entourage has taken over the hotel’s fourth-floor suites.

One source said, “It was to be a five-course dinner hosted by the president. Secret Service have been combing the hotel all weekend, and the entire food court and first floor were to be locked down.” A White House spokesman confirmed, “The president isn’t going to New York tomorrow, the trip has been postponed . . . because of the Arizona tragedy.”

The king, 86, underwent surgery at New York Presbyterian in November for a herniated disc complicated by a blood clot on his spine. He left the hospital in December and moved to the Waldorf-Astoria to recover.

But sources said he’s since taken up the Plaza’s entire fourth floor for his entourage, including his personal chef. The White House has kept a close eye on his progress. Vice President Joe Biden visited his family in the hospital on Dec. 15, and on Friday, Secretary of State Hillary Clinton met with him at The Plaza.

Obama also spoke with Abdullah on Dec. 26 from his Hawaii vacation to wish him well. In a statement, the White House said the king congratulated him on winning Senate approval of a nuclear-arms-reduction treaty with Russia: “The president thanked him and told him that he looked forward to working closely together in the coming year.” The US announced last year it plans to offer the Saudis $60 billion in fighter jets and helicopters.

Reps for the Saudi royal family didn’t get back to us and reps for The Plaza declined to comment.