Some Washington, D.C., bureau chiefs knew as early as last Thursday that President Barack Obama was planning a secret trip to Afghanistan on Sunday.

Ed Chen, president of the White House Correspondents Association and a Bloomberg News White House reporter, said White House Press Secretary Robert Gibbs met with a group of D.C. bureau chiefs Thursday to advise them of the trip.

But all were sworn to secrecy.

“They were told of the trip and to please keep it silent,” Chen said.

Dean Baquet, Washington bureau chief for The New York Times, said he did not attend the meeting with Gibbs, but a Times deputy bureau chief did. “We knew about it in advance and that let's us cement who is going to go,” Baquet said. “We didn't let anyone know and there is a legitimate argument for that.”

When Obama arrived Sunday for the surprise visit, press outlets were not allowed to report on it until he reached the presidential palace.

“You have a president of the United States flying into a war zone,” Baquet said about the reasoning for the secrecy.

Chen said most White House reporters had suspected Obama would make such a trip to Afghanistan sometime this year: “In some ways it was not a surprise.”