More than 120 former GOP national security officials endorsed Democratic presidential nominee Joe Biden on Thursday, joining a cadre of Republican groups to oppose the reelection of President Trump.

The group, called Former Republican National Security Officials for Biden, launched in August with 70 members backing the former vice president. It announced Wednesday that an additional 56 people joined the group, bringing its total membership to 129.

New officials to join the group include Greg Brower, a former FBI assistant director; Larry Pfeiffer, a former CIA chief of staff; and Olivia Troye, a former special adviser to Vice President Mike Pence. Others worked as senior national security officials in the Republican administrations of former Presidents Ronald Reagan, George H. W. Bush and George W. Bush.

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On Thursday, the group began running full-page newspaper ads in seven battleground states that will play a pivotal role in the Nov. 3 election: Pennsylvania, Texas, Florida, Wisconsin, Arizona, North Carolina and Michigan.

The group accuses Trump of being unfit for the White House, referencing the Atlantic article that alleged the president had referred to American Marines who died in World War I as "losers" and "suckers." Trump has vehemently denied the report.

The former officials also said that Trump had deliberately downplayed the coronavirus pandemic.

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“President Trump has made us less safe because of the ways in which he has disregarded facts, criticized those in the intelligence community, and dismissed and demeaned the allies around the world on which we rely for our national security," former National Counterterrorism Center Director Michael Leiter said in an ad that will run nationwide.

The new endorsements from the group come just a few days after a group of 70 senior government officials who worked with various Republican administrations dating back to Richard Nixon backed Trump's reelection bid, citing his accomplishments on foreign policy and national security.

In an open letter, 70 former officials, including governors, senators, national security advisers, military generals and ambassadors from the Trump, George W. Bush, George H.W. Bush, Reagan, Nixon and Ford administrations, lauded the president for pursuing a "strong foreign and national security policy in America's interests."

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"We also believe that a president’s duty and loyalty are owed, first and foremost, to the American people, and not the international community, which is consistent with strengthening our alliances and friendships," the letter said. "For all of these reasons, we have concluded, that Donald J. Trump should be re-elected as President of the United States."