Korean dissident Kim Dae Jung arrived in Washington last night to an emotional and jubilant welcome from more than 300 supporters at National Airport.

In an arrival statement, the dissident publicly thanked President Reagan and Sen. Edward Kennedy (D-Mass.) for their efforts in securing his release.

"Thank God, the American people and world opinion," Kim said through an interpreter.

Kennedy has worked for several years to free Kim, and the Democrat's foreign affairs adviser Jan Kalicka was in the crowd.

The bustling throng chanted, "Long live Kim Dae Jung!" Some came from as far away as Canada, and many carried placards in Korean and English saying "We shall overcome."

Kim -- who only hours before had been released from a Seoul hospital that he called a "jail" in his remarks to reporters -- walked without support and appeared healthy. He gave no indication of needing immediate medical care, although the official reason given for his release was the need to come here for treatment.

Kim declined to answer political questions, pleading that he had to get reacquainted with world events. He said his eventual aim was to return to Korea and work for the "peaceful reunification of my fatherland and the democracy of my fatherland."

Kim, accompanied by his wife and two sons, Hong Up, 30, and Hong Kul, 23, said that he would go to Harvard to accept a longstanding invitation to be a visiting fellow.