Who was the mediator of Tashkent declaration?

Who was the mediator of Tashkent declaration?

اعلان تاشقند کا ثالث کون تھا؟
Explanation

The Tashkent Declaration was signed between India and Pakistan on 10 January 1966 to resolve the Indo-Pakistani War of 1965

The Tashkent Declaration was a peace agreement between India and Pakistan. 

Through the mediation of the Soviet Union Tashkent Agreement held between India and Pakistan 

Tashkent Declaration was signed president of Pakistan Ayub Khan and by India’s Prime Minister Lal Bahadur Shastri 

ND11-2-2023