Decades-old classified documents related to the assassination of U.S. President John F. Kennedy have been declassified following an order by Donald Trump, revealing a connection to Bulgaria. Among the newly released records is a report indicating that a warning about the planned assassination had been sent from Sofia months before the tragic event in Dallas, BNT reports. However, the alert was reportedly ignored by American authorities.

The files include a series of letters signed by an informant named Sergey Chernogo. A woman named Bisera Asenova, with a distinctly Bulgarian name, also appears in the documents, allegedly sharing crucial information regarding the plot. According to Chernogo, in August 1963—three months before Kennedy was assassinated—he was given details about the plan in a room in Sofia.

A document from 1976 found in the declassified archives details his account. Chernogo states that on August 9, 1963, Soviet Consul Vassilev instructed him to relay the information to the U.S. government. Five days later, on August 14, Vassilev’s acquaintance, Bisera Asenova, allegedly visited Chernogo and repeated that Lee Harvey Oswald was a hired assassin who intended to kill Kennedy.

Chernogo claims that the following day, at the Sofia airport, he met with Vice Consul Blackshire from the U.S. Embassy, reporting the details of the assassination plot. Blackshire allegedly assured him that a telegram would be sent to the State Department and provided an address in Washington where further information could be shared. On August 19, after arriving in the U.S. capital, Chernogo reported once again to American intelligence, emphasizing that Oswald would assassinate Kennedy and that Oswald himself would be killed afterward—both of which later transpired.

Little is known about Chernogo’s background beyond his status as a political émigré from the Soviet Union who had obtained American citizenship. Thirteen years after Kennedy’s assassination, he wrote to the FBI, recalling his warnings from August 1963. In his letters, he also accused FBI agents of harassing him and even using gas to induce amnesia.

In one of the testimonies labeled "Secret," he recounts that when he informed authorities Oswald possessed a weapon, the response was dismissive. "I said Oswald had a gun. Let them check it. But the director replied to me—‘You can also have a gun, what’s the point if Oswald has one?’"

Despite the details in the documents, the identity of Bisera Asenova, who allegedly played a role in attempting to prevent the assassination, remains a mystery. Efforts to uncover more information about her are ongoing.