Washington, Oct 20 (IANS): At least 291 former US national security officials have signed a letter endorsing Democratic nominee Joe Biden for President, it was announced on Tuesday.

The latest signatures announced join the 489 national security leaders who had previously endorsed the former Vice President as having "the character, principles, wisdom and leadership necessary to address a world on fire", The Hill news website reported.

In a statement, Michael Smith, executive director of National Security Leaders for Biden, the group that organized the letter, said: "The initial release of the letter was a clarion call to so many patriotic Americans who believed they must do their part to elect Joe Biden.

"It is no secret that our nation is in turmoil. We believe Joe Biden and Kamala Harris will help truly unite the United States and navigate this nation through this troubled time."

The new endorsements also add 81 retired general and flag officers, bringing the total number to 284 retired officers on the letter.

The first batch of signatures on the letter included former vice chairman of the Joint Chiefs of Staff Gen. Paul Selva and former Coast Guard Commandant Adm. Paul Zukunft, both of whom served under President Donald Trump.