File: President Obama and then-Secretary of State Hillary Clinton (Photo by Win McNamee/Getty Images)

Former secretary of state Hillary Rodham Clinton writes in her soon to be released memoir that she formed an "unexpected partnership and friendship" with President Obama.

Reflecting on her tenure as the nation's chief diplomat, Clinton writes, "These years were also a personal journey for me, both literally (I ended up visiting 112 countries and traveling nearly one million miles) and figuratively, from the painful end of the 2008 campaign to an unexpected partnership and friendship with my former rival Barack Obama. I’ve served our country in one way or another for decades. Yet during my years as Secretary of State, I learned even more about our exceptional strengths and what it will take for us to compete and thrive at home and abroad."

Clinton's memoir "Hard Choices" is set to be released on June 10. An author's note excerpt was released Tuesday morning on the book's Web site. Audio of the excerpt was also posted online.

Governing requires making difficult choices, Clinton writes, citing Obama's decision to send Navy SEALs on a mission to go after after Osama bin Laden as among the toughest she took part in.

"The President’s top advisors were divided. The intelligence was compelling, but far from definitive. The risks of failure were daunting," Clinton writes.

As tends to be the case "with the benefit of hindsight, I wish we could go back and revisit certain choices," writes Clinton of her time as secretary of state. "But I’m proud of what we accomplished."

Clinton says she didn't write her book for "followers of Washington’s long-running soap opera," but rather for "Americans and people everywhere who are trying to make sense of this rapidly changing world of ours, who want to understand how leaders and nations can work together and why they sometimes collide, and how their decisions affect all our lives."

Among titles she weighed for her book, "Hard Choices" was the one that "best captured my experiences on the high wire of international diplomacy and my thoughts and feelings about what it will take to secure American leadership for the 21st century," Clinton writes.

"When I began this book, shortly after leaving the State Department, I considered a number of titles. Helpfully, the Washington Post asked its readers to send in suggestions. One proposed 'It Takes a World,' a fitting sequel to It Takes a Village. My favorite was 'The Scrunchie Chronicles: 112 Countries and It’s Still All about My Hair,'" Clinton says.