Iran's President Hassan Rouhani said Friday that the time isn't right for another phone conversation or a meeting with President Barack Obama "because of the sensitivity that still exists between the two countries."

One year ago, Obama and Rouhani came close to ending the decades-long freeze on face-to-face meetings between their countries' leaders. Obama and Rouhani spoke by telephone for 15 minutes as the Iranian leader headed to the airport after his first appearance at the U.N. General Assembly's annual meeting of world leaders.

It was the first time the presidents of the United States and Iran had talked directly since the 1979 Iranian revolution and siege of the American embassy. The conversation was hailed as an historic breakthrough.

Rouhani, peppered with questions about a repeat conversation at a news conference before heading home after this year's ministerial meeting, said: "Not a meeting nor a telephone call had been included in the agenda nor been planned for, ... nor intended to be a part of our visit this year to the U.N. General Assembly."

Rouhani said there must be substantive reasons with "high objectives" for conversations between world leaders. If not, he said, "telephone calls are somewhat meaningless."

The Iranian president said the time is not ripe as there still is too much sensitivity between the two countries. A phone conversation between the two leaders "would only be constructive and fruitful when it is done according to a precisely laid plan with precisely clearly stated objectives," Rouhani said. "Otherwise it will never be constructive or effective."

An important first step would be for Iran and six major powers including the United States to reach agreement on the country's disputed nuclear program.

He said progress so far "has not been significant," and the pace must be speeded up if the Nov. 24 deadline for a final agreement is to be reached. But despite the slow pace, he said, Iran believes an agreement can be reached if both sides "show courage, the will, the strength ... along with the appropriate needed action and the needed flexibility."

Once there is a nuclear agreement, Rouhani said, the first step will be restoring trust between United States and Iran, which remains an obstacle.

"The people of Iran must learn to trust again, and the interlocutors must earn that trust again," Rouhani said.