Nora Shourd, Laura Fattal and Cindy Hickey arrived in Tehran Wednesday after the Iranian government granted them visas to visit their children, jailed since July 2009 after straying into the country from Iraq and arrested on espionage charges, Iran's government-backed Press TV reported.
The families said Shane Bauer, Sarah Shourd and Josh Fattal strayed accidentally into Iran from Iraq at an unmarked border.
Iran's Intelligence Ministry said the three Americans have been treated well in prison despite the seriousness of the charges against them.
"We have treated the U.S. nationals according to our religious principles and on humanitarian grounds, even though these individuals committed an act of espionage by illegally crossing the (western) border into Iran," Iranian Intelligence Minister Heydar Moslehi told reporters Wednesday.
Obama elicited laughter from the assembled guests on more than one occasion, including when he opened his comments by welcoming Mexican President Felipe Calderon and first lady Margarita Zavala to the White House -- "tonight, la Casa Blanca."
The U.S. president noted Mexico is marking the bicentennial of its independence and the centennial of its revolution and said the evening was a celebration of "the bonds we share, as neighbors and as friends."
Getting around to his toast to the guests of honor, Obama said he remembered the enthusiastic children he and his wife met on their visit to Mexico.
"Each of those children has a dream. And yet we know that in life it's not enough to want your dream," Obama said. 'As the extraordinary writer Octavio Paz wrote in one of his poems, you must 'deserve your dream.'
"And so, Mr. President, I propose a toast -- to the dreams of our children. Together, may we realize those dreams. And together, may we deserve them -- by going forward in partnership and respect."
Speaking through an interpreter, Calderon thanked the Obamas and the people of the United States "for your invitation and the generous hospitality with which we have been welcomed during this visit." He went on to speak of the interdependence of the two nations.
"I have said this, and allow me to repeat it: We work with a certainty of what is good for the United States of America is good for Mexico, and if we understand this, at the same time, what is good for Mexico is good for the United States," the Mexican president said.
Continuing in English, Calderon told Obama he liked the quote about dreams.
"I don't know if you and me deserve our dreams, but I know that both of you -- both of us have dreams; those dreams are related with our people and we fight every day in order to deserve those dreams," he said. "And we will reach them."
The 24-year-old Dearborn native is a graduate of the University of Michigan where she earned her bachelor of arts degree in economics, with a minor in business administration.
After completing her reign as Miss USA, she plans to attend law school. She enjoys traveling, running, dancing, kickboxing, and especially likes playing football and watching the NFL, NBC said.
Throughout Sunday night's 2-hour event, the contestants competed in three categories: swimsuit, evening gown and interview.
Kristen Dalton, Miss USA 2009, crowned her successor at the conclusion of the telecast, before an estimated worldwide viewing audience of more than 250 million, NBC said.
First runner-up this year is Miss Oklahoma USA Morgan Elizabeth Woolard. Miss Virginia USA Samantha Casey was second runner-up and Miss Colorado USA Jessica Hartman and Miss Maine USA Katie Whittier round out the top five.
Serving as co-hosts of the beauty pageant were chef and "The Celebrity Apprentice" contestant Curtis Stone and "Today" show co-host and correspondent Natalie Morales.
Iranian Foreign Ministry spokesman Ramin Mehmanparast said Monday the Iranian government will send about 1,200 kilograms (2,640 pounds) of uranium enriched at 3.5 percent for 120 kilograms (264 pounds) enriched at 20 percent, Iranian-backed Press TV reported.
The International Atomic Energy Agency will receive an official letter about the agreement "within a week," Mehmanparast said.
The exchange will occur about a month after Iran received official approval from the Vienna Group, made up of representatives from Iran, France, Russia, the United States and the IAEA, Press TV said.
Diplomats said the agreement -- the result of trilateral talks among Iran, Turkey and Brazil -- could revive an earlier U.N.-backed proposal for Iran to exchange fuel outside its borders, The New York Times reported.
Word of the agreement began filtering out Sunday after talks in Tehran involving Brazil's president, Luiz Ignacio Lula da Silva, Turkish Prime Minister Recep Tayyip Erdogan and Iranian President Mahmoud Ahmadinejad. A Turkish Foreign Ministry spokesman said Iran and Turkey reached agreement on the "principles" to revive the stalled nuclear fuel-swap deal backed by the United Nations.
Unclear was whether U.S. President Barack Obama's administration, which has insisted on a new round of sanctions over Iran's nuclear program, would accept a new version of the original United Nations-based deal for a fuel exchange. The original terms were thought to be desirable to the United States and Western allies because Iran would have temporarily relinquished most of its uranium.
Mehmanparast said Turkey, which doesn't enrich uranium, agreed to serve as the venue for the fuel exchange, the Los Angeles Times reported. It wasn't clear whether Turkey would be a guarantor for the low-enriched uranium or if the material would be shipped to a nation with refinement capacity.
Just before liftoff from Kennedy Space Center, Launch Director Mike Lienbach wished the six crew members "good luck and Godspeed" and told them to "have some fun out there."
Atlantis reached orbit without incident and was on its way toward the space station at about 17,500 mph, NASA said. The three main engines were shut off and Commander Ken Ham and his crew were to use smaller orbital maneuvering system engines to lift the shuttle higher into space for its two-day pursuit of the space station.
Atlantis lifted off and cleared the launch tower at 2:20:50 p.m. EDT and at 2:23:33 p.m. the twin solid rocket boosters fell away as designed, allowing the three main engines to push the spacecraft faster and higher.
In the minutes leading to liftoff, NASA engineers resolved concerns about the discovery of a ball bearing near the shuttle's payload bay.
The all-male shuttle crew members are on a 12-day mission to deliver an integrated cargo carrier and a Russian-built research module. The are to return to Earth May 26.
Just two shuttle flights are scheduled after Atlantis lifts off -- one flight by Discovery and one by Endeavour. NASA plans to end the 3-decade-old program by the end of this year.
The station is to remain operational until at least 2020 with NASA astronauts reaching it via Russian Soyuz spaceships until private companies develop spacecraft that can reliably ferry people into space.