Katie Couric showed off the sparkling diamond engagement ring Wednesday night at the U.S. Open tennis tournament in New York.

The ring appears to boast a large, cushion-cut solitaire diamond, placed in a white gold or platinum setting. (See photos of Katie Couric's new ring.)

The 56-year-old talk show host and veteran journalist, who was widowed in 1998 after her husband died of colon cancer, officially announced her engagement with an exclusive interview in this week's issue of People magazine.

The Katie host said she was "stunned" by John Molner's marriage proposal.

"It took me a while to say yes, because I was so confused!" Couric told PEOPLE of the proposal by Molner, 50, on a beach in East Hampton, N.Y., over Labor Day weekend. "It took a long time for my brain to process what was going on."

"I knew that I wanted this," she said of getting engaged. "I made it a priority, and I pursued it with some purpose."

In early 2012, she met Molner through mutual friends, and they soon hit it off. They first went public with their relationship in April 2012.

Molner will become a stepdad to Couric's two daughters with Monahan, Ellie, 21, and Carrie, 17. 

Couric said their nuptials are likely to take place after her youngest daughter leaves for college.

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