Ariana Grande has hailed Lady Gaga a "literal angel".

Ariana Grande and Lady Gaga (c) Instagram

Ariana Grande and Lady Gaga (c) Instagram

The 'No Tears Left To Cry' hitmaker shared a heartfelt tribute to her pop star pal on her 34th birthday on Saturday (28.03.20), and thanked the 'Star is Born' actress for helping her to change her life.

Ariana, 26, shared a photo of herself and Gaga together and wrote on Instagram: "Happy birthday to a literal angel that has changed my life in many ways!

"I'll tell u more about it later but ... u make my heart feel so full and happy and understood @ladygaga.

"Wishing u all the joy in the world today and every day ! have some pasta !(sic)"

Meanwhile, Director-General of the World Health Organisation, Dr. Tedros Adhanom Ghebreyesus, revealed Gaga spent her birthday sitting in on a call with him so she could find ways to "support the world" amid the ongoing coronavirus pandemic.

Tedros revealed on Twitter he had been speaking to Gaga about the best ways to help those impacted by the global health crisis, and praised the singer for her "compassion and kindness".

He wrote: "A very good call with @ladygaga. I thanked her for her continuing efforts to show compassion & kindness to the world. She is ready to support @WHO in any way possible in the fight against #COVID19. Together!

"And happy birthday @ladygaga! I am so touched that you're spending this moment on finding ways to support the world during #COVID19. I send you my best wishes! Thank you for spreading kindness at such an important moment for all of us! Together! (sic)"

Last week, Gaga postponed the release of her upcoming album 'Chromatica' due to the pandemic.

Taking to her Instagram account, she wrote: "I wanted to tell you, that after a lot of deliberation, I've made the incredibly tough decision to postpone the release of Chromatica. I will announce a new 2020 release date soon."