Several ranking US lawmakers, however, have called for taking action against Iran over the incident.
In particular, US House Minority Leader Kevin McCarthy said on Thursday the US must undertake a "measured response" to Iran.
"Iran directly attacked a United States asset over international waters. This provocation comes a week after they attacked and destroyed two commercial tankers in international waters. There must be a measured response to these actions", McCarthy and Representatives Michael McCaul, Mac Thornberry and Devin Nunes said in a joint statement.
Earlier in the day, Iranian Foreign Minister Javad Zarif said that debris from the US drone was located in Iranian territorial waters.
Zarif stressed that Washington continues to wage "economic terrorism" against the Islamic republic. Tehran is not seeking war, but just wants to "defend [its] skies, land and waters", he added.
The US Air Force Central Command refuted Tehran's claims that the RQ-4 UAV (unmanned flying vehicle) was shot down over its territory and said that the incident was an attempt to disrupt US ability to monitor the area following recent threats to international shipping and the free flow of commerce.
Last week, two oil tankers, the Kokuka Courageous and the Front Altair, were reportedly attacked in the Gulf of Oman near the Strait of Hormuz. While the causes of the incident remain unknown, the United States claimed that Iran had sabotaged the vessels. The US military subsequently released a video showing alleged Iranian forces removing an unexploded mine from one of the tankers. The footage, however, did not show any boat names or flags that would substantiate the claims.
Iranian Foreign Minister Zarif accused the United States, Israel and Saudi Arabia of coordinating a campaign to falsely blame Iran for the attacks.
Tensions between Tehran and Washington have been mounting ever since the abrupt May 2018 US withdrawal from the 2015 Iran nuclear deal. A year later, the situation has deteriorated, with the US implementing new sanctions against the Islamic Republic targeting the country's finance, transport, military and other spheres.
In May this year, Iran announced that it had partially discontinued its commitments under the landmark accord and gave Europe 60 days to ensure Iran's interests were protected under the agreement.