Dr Anwar Gargash says Qatar's accusation that an Emirati fighter jet violated its airspace is "untrue and confused".
The Minister of State for Foreign Affairs was responding to a complaint by Qatar to the United Nations secretary general and Security Council that an Emirati jet entered its economic zone at 9.45am on December 21. Hours after he refuted the allegation, Doha claimed there had been another violation of its airspace by an Emirati military plane on January 3.
"We are working to respond officially to [the complaint] with evidence and proof," Dr Gargash tweeted on Friday. "What we see is an escalation and unjustified.
"What has been happening under the table is now taking place in the open," he added.
There has so far been no official UAE response to the second complaint sent to UN secretary general Antonio Guterres and Security Council president Kairat Umarov, which alleges that an Emirati aircraft entered Qatar's airspace at 10.10am on January 3 while flying from the UAE to Bahrain.
The diplomatic spat comes as the UAE, along with Saudi Arabia, Bahrain and Egypt, continues to boycott Qatar over its support for extremist groups and its meddling in the affairs of its neighbours.
On Thursday, Dr Gargash said Qatar's inability to provide evidence that it does not support terrorist groups and activities has led to it creating a string of "weak" excuses.