U.N. Ambassador Jeane J. Kirkpatrick, who was scheduled to see President Reagan today to discuss her future, yesterday postponed the meeting because of what an aide called "pressing business requiring her attention at the United Nations."

The aide, who asked not to be identified, also said he could give no indication of when the appointment might be rescheduled. He said: "There is a lot of pressing U.N. business that requires her attention and time. When she can shift her attention to what comes after the U.N., she will do so."

The postponement came after Reagan, in an interview with The Washington Times published yesterday, indicated that he seems resigned to Kirkpatrick's departure from the administration.

Despite pressure from her conservative admirers, Reagan said he did not see a foreign policy post available "that would be worthy of her."

The president indicated earlier that Kirkpatrick could become a special White House counselor or virtually have her pick of foreign embassies. However, she has let it be known that she is interested only in a top post, such as secretary of state, defense, director of the CIA, or national security affairs adviser. Reagan has asked the incumbents to stay on the job in all these posts.

Some administration officials have interpreted Reagan's remarks in The Washington Times as a signal to Kirkpatrick that he will not be pressured into granting her wishes.

As a result, it was not immediately clear whether the postponement of their meeting was related to the maneuvering between administration moderates and hard-liners about finding a way to keep her in a position to influence administration foreign policy.

Kirkpatrick could not be reached for comment. Her aide, who was authorized to speak for her, said Kirkpatrick originally had been scheduled to meet with Reagan after a Cabinet meeting today.

But, he added, the Cabinet meeting was canceled, and Kirkpatrick called the White House late yesterday to say that since the Cabinet meeting had been scrubbed, she wished to remain in New York to attend to business in the U.N. Security Council and to participate in a General Assembly debate.

Conservatives, who admire Kirkpatrick's outspoken and tough views on issues such as combating leftist influence in Central America, want her to remain in the administration as an ally of such officials as Defense Secretary Caspar W. Weinberger and CIA Director William J. Casey.

However, the idea of making her national security affairs adviser in the White House, a post that could give her pivotal influence over policy, has been strongly opposed by moderates such as Secretary of State George P. Shultz and White House chief of staff James A. Baker III.

Last year, they thwarted a conservative drive to install Kirkpatrick in the White House adviser's post by getting Robert C. McFarlane named to that job.

Kirkpatrick also has made known her belief that continued opposition from Shultz and Baker would block her from getting a key policy-making job despite Reagan's often stated desire to retain her services in his second term.

Sources close to Kirkpatrick have said she is likely to return to private life and wait for possible personnel shifts in the administration in a year or two.