Madonna has said she is "on the road to recovery" in her first statement since a bacterial infection left her in a hospital's intensive care unit.
On social media, the singer said "my focus now is my health" and thanked her fans for their "positive energy", reports BBC.
The star, 64, said: "I assure you, I'll be back with you as soon as I can!"
The pop star said her current plan was to reschedule her forthcoming North American concerts and begin her Celebration Tour in the UK in October.
In the statement, she wrote: "Thank you for your positive energy, prayers and words of healing and encouragement. I have felt your love.
"I'm on the road to recovery and incredibly grateful for all the blessings in my life.
"My first thought when I woke up in the hospital was my children.
"My second thought was that I did not want to disappoint anyone who bought tickets for my tour. I also didn't want to let down the people who worked tirelessly with me over the last few months to create my show. I hate to disappoint anyone.
"My focus now is my health and getting stronger and I assure you, I'll be back with you as soon as I can!
"The current plan is to reschedule the North American leg of the tour and to begin in October in Europe."
She had been due to start the greatest hits tour in Canada on Saturday, 15 July. The European leg is scheduled to begin with four nights at London's O2 Arena from 14 October.
'Care and support'
She finished her statement by saying: "I couldn't be more grateful for your care and support."
It comes two weeks after her manager Guy Oseary revealed the star had developed a "serious bacterial infection" on 24 June, which led to "a several day stay in the ICU".
At the time, he said she would "need to pause all commitments, which includes the tour".
Madonna's greatest hits span several decades - including Into The Groove (1985), Like A Prayer (1989), to Vogue (1990) and Hung Up (2005) to name a few.
In announcing the tour back in January, she told fans: "I am excited to explore as many songs as possible in hopes to give my fans the show they have been waiting for."
It is likely that she was in the final stages of a rehearsal regime when she became ill.
She called off a number of shows in her more experimental, theatre-based Madame X tour in 2019 and 2020 because of knee and hip injuries.