Russia's Sputnik V coronavirus vaccine will be tested in the UAE, the government said on Monday.
Phase-3 trials will be overseen by Abu Dhabi's public hospital operator Seha, the Ministry of Health and Prevention and the Department of Health Abu Dhabi.
The announcement was made after a phone call between Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the Armed Forces, and Russian President Vladimir Putin.
The UAE trials of Sputnik V vaccine are the second to be held abroad, after testing in Belarus. A further trial is expected to begin in Venezuela soon.
"The UAE is committed to the global fight against Covid-19," UAE Health Minister Abdulrahman Al Owais said.
"We are pleased to support this process and welcome partnerships between UAE organisations and international players."
The trial results will be released before the end of November, state news agency Wam reported.
Russia registered Sputnik V as the world's first coronavirus vaccine, even before the Phase-3 trials began.
It has been introduced in limited numbers to senior Russian figures, including one of Mr Putin's daughters, and thousands of volunteers.
Kirill Dmitriev, head of the Russian Direct Investment Fund, which has financed Russia's vaccine work, was in Abu Dhabi for the announcement.
"We are planning to expand in several other countries over the coming months, and we are delighted that Abu Dhabi will be the first place in which we do so in the Middle East," Mr Dmitriev said.
He has explained how Sputnik V, produced by Moscow's Gamaleya National Research Institute, differed from other vaccines.
It is based on two human adenoviruses – common viruses that cause fever and cold and flu-like symptoms – that were rendered harmless and genetically engineered to carry coronavirus genes.
That is in contrast with some other vaccines that use adenoviruses from chimpanzees.
“Countries have a choice to make and we think they’ll focus on a portfolio of different vaccines,” Mr Dmitriev said recently.
“But we’re absolutely sure that a human adenovirus vaccine will be in the portfolio of most countries.”
Other medicine, including Chinese drug maker Sinopharm's vaccine, were created from weakened coronaviruses or those that have been killed with chemicals and re-engineered to protect the body from infection.
"We have enough capacity originally only for Russia," Mr Dmitriev told CNN's Connect the World programme in Abu Dhabi.
"We will we be inoculating our people, massively, from the end of the month, early November, and all of the vaccine produced will be for Russia.
"So this is why we need productions in India and Brazil to manufacture for the rest of the world."
The UAE was chosen as a partner for Sinopharm's Phase-3 trial in July.
More than 30,000 volunteers were part of the process and more were later sought in limited numbers from Bahrain and Jordan.
One of the reasons for holding trials abroad is to ensure volunteers are from a broad variety of ethnicities and backgrounds.
The UAE is home to about 200 nationalities, whereas China and Russia are largely homogenous societies.
An early version of the vaccine was approved by Emirati authorities for use by frontline workers and others.
Senior officials, including Mr Al Owais, have taken the vaccine.