The UN has said it will investigate the detention of the Venezuelan foreign minister as he tried to leave New York after a UN General Assembly session.
Mr Maduro says his detention was a breach of international law
Nicolas Maduro said he was mistreated by US airport security staff in revenge for Venezuela's criticism of President George W Bush.
He has refused to accept an apology from the US state department.
The US ambassador to the UN, John Bolton, has said the incident was "Venezuelan street theatre".
Screeners at John F Kennedy International Airport are said to have grown suspicious when Mr Maduro used cash to purchase a one-way ticket to Miami shortly before the flight was due to leave on Saturday.
Mr Maduro told Venezuelan television that he was detained for an hour and 40 minutes, and had his passport and plane ticket temporarily taken away.
He said he was verbally abused, threatened with being strip-searched, and that authorities at one point ordered him and other officials to spread their arms and legs and be frisked.
He alleged this was a US reprisal for a speech by Venezuela's leftist President Hugo Chavez at the General Assembly's annual session, in which he called his US counterpart "the devil", "a liar" and a "tyrant".
The US state department issued an apology, saying that airport security staff had questioned the foreign minister, and then US diplomatic security was sent to the airport to resolve the issue.
The minister was told he could board the plane before it took off but he chose instead to return to New York City, the state department added.
Mr Maduro returned to Caracas early on Monday.
Stephane Dujarric, a spokesman for UN Secretary General Kofi Annan, said legal expert Nicolas Michel had been asked to gather the facts about the incident after Venezuela lodged a complaint.
"We are trying to work with both the Americans and the Venezuelans to get past this unfortunate incident as quickly possible," Mr Dujarric told a media briefing. "I don't think anybody wants to escalate this."
Earlier on Monday, Mr Bolton dismissed the Venezuelan claims out of hand.
"There was no incident at the airport. This was Venezuelan street theatre," he told reporters.
"He did not request the courtesies we would have extended to get him through the airport.
"He purchased his ticket at a time and in a manner and with funding such that he was asked to go to secondary screening and he objected to that, and the first thing he did was call the press and speak to them in Spanish. This was propaganda."
Relations between the South American nation, a major oil supplier, and the US have deteriorated in recent years.
Mr Chavez accuses the US of plotting to overthrow and assassinate him, charges Washington denies.