WASHINGTON - The Obama administration said Monday that it had delivered a formal request to Iran for the return of a U.S. surveillance drone captured by Iranian armed forces, but is not hopeful that Iran will comply.

President Obama said that the United States wants the top-secret aircraft back. "We have asked for it back. We'll see how the Iranians respond," Obama said during a White House news conference with Iraqi Prime Minister Nouri al-Maliki on Monday.

He would not comment on what the Iranians might learn from studying the downed aircraft.

Secretary of State Hillary Rodham Clinton and Defense Secretary Leon Panetta said they were not optimistic about getting the drone back because of recent Iranian behavior that Clinton said indicated "that the path that Iran seems to be going down is a dangerous one for themselves and the region."

"We submitted a formal request for the return of our lost equipment as we would in any situation to any government around the world," Clinton said at a State Department news conference with British Foreign Secretary William Hague.

Panetta said the request to return the drone was appropriate. "I don't expect that that will happen. But I think it's important to make that request."

Neither Obama nor Clinton would provide details of the drone request, but diplomatic exchanges between Washington and Tehran are often handled by Switzerland, which represents U.S. interests in Iran. The State Department said Monday that the Swiss ambassador to Iran met with Iranian foreign-ministry officials last week but refused to say what they discussed.

Iran TV reported earlier Monday that Iranian experts were in the final stages of recovering data from the RQ-170 Sentinel, which went down in Iran this month. Tehran has cited the capture as a victory for Iran and displayed the nearly intact drone on state TV. U.S. officials say the aircraft malfunctioned and was not brought down by Iran.

Despite the incident, Clinton said the administration and its allies would continue to push Iran to engage over its nuclear program while increasing pressure on the regime with new, enhanced sanctions.

Standing beside Clinton, Hague agreed.

"We're not giving up on engagement with Iran, but on a number of occasions Iran has behaved in a way in recent weeks and months which has intensified confrontation with the rest of the world," he said. "We have seen an increasing predilection for dangerous and illegal adventures on the part of at least parts of the Iranian regime."

Clinton and Hague referred to the storming of British diplomatic compounds in Tehran, allegations that Iran tried to arrange the assassination of the Saudi ambassador to the United States, Iran's support for militant groups, and its continued defiance of demands to prove its nuclear program is peaceful.