Space agency NASA is to assemble a team of scientists to investigate a "national security" issue.
They will examine "unidentified aerial phenomena" or NASA in the latest sign of the seriousness with which the US government is taking the issue.
The focus will be on identifying available data, the best ways to gather it in future and how it can use that information to improve scientific understanding of the issue.
NASA tapped David Spergel, who formerly headed Princeton University's astrophysics department, to lead the scientific team and Daniel Evans, a senior researcher in NASA's Science Mission Directorate, to orchestrate the study.
A team of scientists will gather in autumn and spend around nine months developing a public report on its findings, Evans said.
NASA will spend "anywhere from a few tens of thousands of dollars" to no more than £80,000 ($100,000) on the effort, Evans added.
The announcement comes a year after the US government issued a report by the Office of the Director of National Intelligence and a Navy-led task force, detailing observations mostly by Navy personnel of "unidentified aerial phenomenon," or UAPs.
Two Pentagon officials testified on May 17 at the first congressional hearing on UFOs in a half
century.
Thomas Zurbuchen, the chief of NASA's science unit, told reporters: "We're looking at the Earth in new ways, and we're also looking the other way, at the sky, in new ways.
"What we're really trying to do here is start an investigation without an outcome in mind."
US officials have described UAPs or UFOs as "a national security issue", which NASA echoed.
"Unidentified phenomena in the atmosphere are of interest for both national security and air safety.
"Establishing which events are natural provides a key first step to identifying or mitigating such phenomena, which aligns with one of NASA's goals to ensure the safety of aircraft,"
Last year's report said US defense and intelligence analysts lacked sufficient data to determine the nature of UAPs observed by military pilots.
It questioned whether they are advanced earthly technologies, atmospherics or of an extraterrestrial origin.
The two Pentagon officials last month acknowledged many observations remain beyond the government's ability to explain.
NASA then said: "There is no evidence UAPs are extraterrestrial in origin."
Zurbuchen said: "The agency's involvement is aimed at providing more data, with an aim to leverage NASA's scientific talent, satellites and sensors otherwise tasked with monitoring Earth's climate or observing atmospheric conditions."
Evans added: "The first step is to figure out what data is at hand"
NASA's involvement in Pentagon efforts to characterize UAPs has been previously acknowledged by US officials.
The Pentagon has made public some video of enigmatic objects showing speed and maneuverability.
Footage also exceeded known aviation technology and lacked any visible means of propulsion.
