Former president Jimmy Carter told Princeton University upperclassmen at a private meeting today that he was not as "effective" in the White House as he wanted to be and "might have been more forceful" with Iran, the students said.

Carter also told the invitation-only group that "the American press to some extent hampered his ability to act," according to Steve Yelenoski. The senior from Houston said the former president claimed the media "deliberately distorted information and didn't check out all the facts."

Carter also said "he might have been more forceful in dealing with Iran," according to Yelenoski.

He also admitted "he wasn't as effective as a president as he could have been," said David Huebner, a junior from Pennsylvania.

Carter's remarks came during a question-and-answer session iwth upperclassmen studying the American presidency at the Woodrow Wilson School of Public and International Affairs.

He is spending time on the Ivy League campus seeking advice of scholars in preparing his memoirs.

Carter "doesn't want to write a history of his presidency . . . but wants to write about problems in getting his program approved," Huebner said.

Carter's only reference to his successor was that he "was gratified to read today that Ronald Reagan is having some difficulties with Congress," Yelenoski said.

Carter later told reporters he would "like to see Reagan succeed."

Doing some reflecting of his own in Los Angeles today, former vice president Walter F. Mondale said the humiliation of the Iranian crisis and the letdown of the failed hostage rescue mission were major factors in Reagan's victory.

Mondale said that after the rescue attempt "Americans said, 'What has happened to our country?' That, plus the constant humiliation that was also heaped on the American people," combined to help defeat the Democratic ticket.

Mondale said he would not second-guess decisions made in the White House during the Iranian crisis.