UN is an international organisation founded after World War II aims to provide a dialogue platform between countries, fortifying international corporation and preventing future wars. There are currently 193 members lead by five permanent members of the Security Council - US, Russia, UK, France, and China. The organization currently has six principal organs: General Assembly, Security Council, Economic and Social Council, Secretariat, International Court of Justice, and the Trusteeship Council.
Obama, Rowhani come close to a historic handshake at UN
Agence France-Presse in New York
The US and Iranian presidents, Barack Obama and Hassan Rowhani, came agonisingly close to a historic handshake on Tuesday, officials said.
"It got so close that they had chosen the room and ordered some water," said a diplomat with knowledge of talks between the two sides on holding a breakthrough encounter.
Leaders from Iran and the US have not met since the 1979 Islamic revolution brought open hostility to their contacts, particularly over Iran's contested nuclear programme.
Obama and Rowhani, who since winning an election in June has said he wants to improve relations, spoke several hours apart at the UN General Assembly. They were never in the same room together.
The US appears to have taken the lead in pressing for a discussion of just a few minutes.
The two sides discussed a possible meeting, but in the end it was "too complicated" for Iran, said a senior US official.
Rowhani told CNN how "preparation" for a meeting was carried out.
"The United States declared its interest in having such a meeting and in principle could have, under certain circumstances, allowed it to happen," he added.
"I believe we didn't have sufficient time to really co-ordinate the meeting."
Rowhani said "ice-breaking" was still going ahead. The environment was changing as a result of "the will of the people of Iran to create a new era of relations".
"We indicated that the two leaders could have had a discussion on the margins if the opportunity presented itself," a senior US administration official said.
"The Iranians got back to us; it was clear that it was too complicated for them to do that at this time given their own dynamic back home."
The approach for a meeting appears to have been a part of what Obama told the UN assembly would be efforts to "test" Iran on its willingness to improve relations.
And US officials said Obama remained open to a meeting with Iran's top leaders, who have often excoriated their US counterparts.
"Our assessment is while Rowhani has been elected with a mandate to pursue a more moderate foreign policy … the issue of the relationship between the United States and Iran is incredibly controversial within Iran," said the senior US official.