Speaking at the Chatham House forum in London on Monday, the UAE foreign minister, Anwar Gargash, twice denied the veracity of the claims.
Abu Dhabi in response to the newspaper's article refuted the allegations and said that the story is false.
Anwar Gargash denied as false a story in the Washington Post that cited USA officials saying the UAE had orchestrated the hack of Qatar's state news agency.
The dispute began in May when Qatar's Emir Sheikh Tamim bin Hamad al Thani was reported to have made statements on the state news agency supporting Iran.
According to the official agency, Gargash said in a speech at the Royal Institute of International Studies in London, during a lecture entitled "The Gulf Crisis: its Causes and What will Lead", which dealt with the crisis with Qatar, including its background, consequences and prospects.
The UAE, Saudi Arabia, Bahrain and Egypt responded by blocking Qatari media.
The UAE government planned the infamous May 24 hacking of QNA, states the report citing USA intelligence officials who were not named because of the "sensitive" character of the matter. Previously, US media, citing the Federal Bureau of Investigation, blamed the attack on "Russian hackers".
While much of what Qatar's critics charge is true, you also have to consider the source. Funding, supporting, and enabling extremists from the Taliban to Hamas [terrorist organizations, outlawed in Russia] and Qadafi.
As a result of the hacking, fabricated news was posted on the agency's website, partially provoking a rift between the emirate and other states of the region.
Qatar signed a memorandum of understanding last week with the U.S. on tackling the presence of designated terrorists and promised new measures on sending financing to blacklisted groups. "You can not be both our friend and the friend of Al Qaeda".
"What we know now is that Qatar is admitting that the list is worthy, that the list needs to be looked at, and that they need to change some of their laws to ensure that there is a proper process to cover this list", he said. UNSC Resolution No. 2309 voices concerns that civil aviation can be used to transport foreign terrorists, they added. "But the issue is that we are being hurt, and the world is being hurt, by a state that has $300bn (£230bn) and is the main sponsor of this jihadist agenda".