Kohli took over India's limited-overs captaincy in 2017, succeeding Mahendra Singh Dhoni.
The decision, Kohli said, was taken after consulting head coach Ravi Shastri, his heir apparent Rohit, BCCI President Sourav Ganguly and secretary Jay Shah.
Virat Kohli captaincy record in T20Is
Kohli has played 90 T20 Internationals scoring 3159 runs with 28 fifties and captained India in 45 of those games winning 27 and losing 14.
He has a winning percentage of 65.11.
The ICC T20 World Cup starts on October 17.
Here's the full text of Virat Kohli's statement on leaving India's T20 captaincy: I have been fortunate enough to not only represent India but also lead the Indian Cricket Team to my utmost capability. I thank everyone who has supported me in my journey as the Captain of the Indian Cricket Team. I couldn't have done it without them - the boys, the support staff, the selection committee, my coaches and each and every Indian who prayed for us to win.
Understanding workload in a very important thing and coming my immense workhand over the last 8-9 years playing all 3 formats and captaining regularly for last 5-6 years, I feel I need to give myself space to be fully ready to lead the Indian Team in Test and ODI cricket. I have given everything to the Team during my time as T20 Captain and I will continue to do in for the T20 Team as a batman moving forward.
Of course, arriving at this decision took a lot of time. After a lot of contemplation and discussions with my close people, Ravi bhai and also Rohit, who have been an essential part of the leadership group, I've decided to step down as the T20 Captain after this T20 World Cup in Dubai in October. I have also spoken to the secretary Mr Jay Shah and the President of BCC1 Mr Sourav Ganguly along with all the selectors about the same. I will continue to serve Indian Cricket and the Indian Team to the best of my ability.