Washington (CNN) Former Pennsylvania Rep. Joe Sestak on Sunday ended his long-shot 2020 presidential bid after failing to gain traction in the race for the Democratic Party's nomination.

"I want to thank you for the honor of running for President of the United States of America," Sestak said in a statement. "It has been an endeavor filled with immeasurable wisdom, passions, humor and insights to, and from, the people of America."

Sestak, who mounted unsuccessful bids for US Senate in 2010 and 2016 , entered an already-crowded Democratic primary field in June hoping to leverage his career in the US Navy into a successful campaign, but did not qualify for any of the major Democratic presidential debates.

"The hour has become late to restore US leadership to this liberal world order, but Iraq is our lesson to remember," Sestak said in a video announcing his campaign in June. "Democrats and Republicans alike who cast their votes for the tragic misadventure in Iraq showed little understanding that while militaries can stop a problem, they can never fix a problem."

Sestak admitted at the time that he was late to the nominating contest, conceding, "My announcement may be later than others for the honor of seeking the presidency," and cited his daughter's recent fight with brain cancer as the reason for his delay.

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