(CNN) CIA officials wondered in the days after President John F. Kennedy's assassination whether Lee Harvey Oswald's efforts to obtain visas to travel to Russia had been part of an escape plan, newly released government documents show.

Oswald made efforts to obtain visas to travel through Cuba to the USSR with his Russian-born wife in the two months prior to the assassination, according to the files, which are among the thousands of pages of documents related to the Kennedy assassination released Friday by the Trump administration.

The records shed further light on how deeply CIA officials delved into Oswald's connections to and communications with the Soviet Union.

The documents say Oswald spoke "terrible hardly recognizable Russian" during his visit to Mexico City to meet with Soviet and Cuban consular officials. The Cuban consulate turned Oswald away, saying he first needed a visa from the Soviets, a process that the Cubans warned could take four months.

"One important question still puzzles us," an official wrote two days after the killing: Was Oswald looking to travel immediately, or did he plan to pocket the visa for later use?

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