Things always move at a hectic pace during meetings around the annual U.N. General Assembly, but Secretary of State Hillary Clinton may raise that bar higher this year.

Within four days, Clinton had already met with 21 heads of state and government and foreign ministers during a marathon schedule of meetings on the sidelines of the annual conclave of world leaders.

Clinton's days this week have been a blur of back to back meetings in hotel suites and meeting rooms near U.N. headquarters.

She has spoken with the presidents of Afghanistan, Pakistan, the Palestinian Authority, and Myanmar as well as the prime ministers of Israel, Turkey and Lebanon. Middle East monarchs and foreign ministers from Belgium, Greece, and Britain have also had meetings with Clinton.

These talks do not include the many speeches she has or will give on issues like the crisis in Africa's Sahel region, the greater involvement of women in the world economy, peace and security in the Middle East, and the importance of water security around the globe.

There also are the remarks before the annual gathering of the Clinton Global Initiative, a meeting with the so-called P5+1 group addressing Iran's disputed nuclear program, and various lunches and dinners with multinational guest lists.

Any down time in Clinton's schedule appears scarce. Her schedule regularly starts before 9 a.m. and usually stretches past 10 p.m. There are quick handshakes for cameras before heading into meetings that run close to an hour on average.

Her staff holds out the possibility of more than 10 additional bilateral meetings if time allows before she is scheduled to return to Washington on Friday evening - possibly 38 overall.

The packed schedule has not gone unnoticed. It has even raised a few eyebrows among some who wonder why Clinton is holding some meetings that would have been handled by President Barack Obama in past years.

In a briefing with reporters this week on Clinton's meeting with Egyptian President Mohamed Morsy, a senior State Department official said that Obama "has very limited time here, and I think that he has to make choices."

A second official added, "these are also relationships that she has helped him to maintain all the way through."

Obama addressed the General Assembly on Tuesday.

White House Press Secretary Jay Carney also reminded reporters that Obama had telephone conversations with the leaders of Israel, Egypt, Libya and others in recent days.

Regardless of her schedule, this will be Clinton's last General Assembly as America's top diplomat. She has said she does not plan to serve in a second term if Obama is re-elected.