Associate Supreme Court Justice Sonia Sotomayor promises that her recent encounter with former Secretary of State Hillary Clinton at a Costco in Arlington, Virginia, was not planned in advance.

"It was not planned, I can assure you," Sotomayor said during an exclusive interview with ABC's George Stephanopoulos for "This Week."

Sotomayor said she was shopping at the store when she heard Clinton was there. She said she didn't see the signs in front of the store noting Clinton's appearance because she used a side door.

"A nice lady at the pharmacy counter … recognized me and we started chatting. And she says, 'Are you here with the other lady?' And I said, 'What other lady?' and she mentioned Madam Secretary and that's how I found out," she said. "I promise."

Clinton, currently considering a run for the presidency in 2016, was at the Costco promoting her new memoir "Hard Choices" when the unexpected rendezvous - which sent politicos aflutter - occurred.

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