Washington (CNN) Cindy McCain is urging people to "get into the arena and fight" for a greater cause as a way to honor her late husband Republican senator John McCain.

"Since his passing, thousands of people have asked how they can do something to honor Sen. McCain. I'll tell you how: Join me in the arena. Fight for a greater cause," she wrote in an op-ed in USA Today published Friday.

She wrote that her husband demanded "the best possible leadership and support for our armed forces, or to empower freedom fighters against dictators around the world, or to demand that perpetrators of torture and human rights abuses be punished, or to make sure our native American communities are treated with dignity and respect."

Days after her husband was laid to rest at the Naval Academy Cemetery this past weekend, McCain said she is grateful for all the kind messages about him.

She added, "John's memory inspires me to be in the arena every day."

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