Updated at 6:10 p.m. on March 16.

The Obama administration has asserted a legal position on the use of drone aircraft to kill suspected terrorists and militants, and officials plan to share the details "at an appropriate moment," according to Harold Koh, the State Department's legal adviser.

National Journal asked Koh, the senior official responsible for international legal issues, to share his views after his public remarks at an American Bar Association speech Wednesday. "I have studied this question," Koh said. "I think that the legal objections that are being put on the table are ones that we are taking into account. I am comfortable with the legal position of the administration, and at an appropriate moment we will set forth that in some detail."

The administration has made drone strikes the centerpiece of its fight against terrorists, but officials have never said why they believe the program complies with international law. A number of legal scholars and international officials have said the killings could violate certain laws of armed conflict, particularly when they're carried out in countries where the United States is not at war, such as Pakistan and Yemen.

Koh gave no indication of when the administration might unveil its legal rationale or what it might entail. But he added, "You can expect a more detailed discussion of this to come." Koh was reluctant to reveal specifics, and he said that the informal venue of a speech was not the appropriate setting to discuss the "complicated" issue.

Some scholars have argued that the United States can justify drone killings of terrorists and militants who would attack Americans on the grounds of self-defense. But, as National Journal reported in January, a growing chorus of experts believes the drone strikes could be deemed extrajudicial killings. The American Civil Liberties Union has filed a Freedom of Information Act request to see all documents that might illuminate the administration's legal thinking on the matter.

Given the political consensus in Washington that drone attacks are effective, safe and palatable tools for killing foreign terrorists, the Obama administration presumably would refute any suggestion the strikes were illegal.

Koh is a prolific writer and authority on human rights, civil liberties and the application of international law, and in his former position as the dean of Yale Law School, he was a vocal critic of the Bush administration's counterterrorism policies. Koh declined an earlier request on the subject of drone strikes, but an extensive survey of his writings suggested that he might take issue with the drone program, at least as it is currently designed.

Archived National Journal Cover Story, Two Parts

• 'Wanted: Dead' -- With little public debate or notice, the Obama administration has significantly stepped up its targeted assassinations.

• Are Drone Strikes Murder? -- A growing number of experts say the legal foundations for targeted drone killings are shaky at best.