William Burns Is Biden’s Choice for C.I.A. Director

John O. Brennan, the former C.I.A. director in the Obama administration, noted that Mr. Burns has long experience working with the agency during his ambassadorial postings and senior State Department posts. Mr. Brennan recounted how he and Mr. Burns gave a classified briefing to the Senate Intelligence Committee on a C.I.A. covert action program.

“He has deep substantive expertise, a wealth of experience working with C.I.A., and he understands the intelligence mission very well,” Mr. Brennan said.

The pick of Mr. Burns suggests that Mr. Biden is putting an emphasis on traditional national security threats. Mr. Burns has long experience with Iran and Russia.

He was instrumental in starting the secret talks with Tehran in the Obama administration, which ultimately resulted in the agreement in which Iran agreed to give up its nuclear program in exchange for relief from punishing sanctions on its economy by six world powers, including the United States. Mr. Trump withdrew from the nuclear deal in 2018, and Mr. Burns could prove critical in aiding the administration in restarting discussions with Tehran.

Mr. Burns sensed an opening to Iran in 2013, with the landslide election of Hassan Rouhani as president. He teamed up with Mr. Sullivan to meet with key Iranians to scope out the parameters of a possible deal. That mission was successful, though it took two more years to negotiate the deal.

Mr. Burns also served as ambassador to Russia from 2005 to 2008, making him a keen observer of President Vladimir V. Putin. Russian interference in American elections has been one of the most important intelligence issues in recent years.

In all, Mr. Burns did two tours in Moscow and speaks Russian, deep knowledge that will serve him well in the new role, colleagues said.