"Yoga has become one of the most powerful unifying forces in the world. It unites individuals, families, society, country and the world," Modi said while leading the fourth International Yoga Day celebrations here in Uttarakhand.

He said that the world has embraced yoga and glimpses of this can be seen in the manner in which the International Day of Yoga is marked every year.

"In fact, Yoga Day has become one of the biggest mass movements in the quest for good health and well-being," he said.

The Prime Minister said that yoga is beautiful because it is "ancient yet modern".

"It is constant yet evolving. It has the best of our past and present and a ray of hope for our future. In yoga, we have the perfect solution to the problems we face, either as individuals or in our society," he said.

In today's fast changing times, yoga binds together a person's body, brain and soul, hence giving one the feeling of peace.

"The way to lead a calm, creative and content life is yoga. It can show the way in defeating tensions and mindless anxiety. Instead of dividing, yoga unites. Instead of further animosity, yoga assimilates. Instead of increasing suffering, yoga heals," he said.

PM Modi said that yoga is one of the most precious gifts from the ancient Indian sages to mankind.

He noted the International Yoga Day is being celebrated across the world. "From Dehradun to Dublin, Jakarta to Johannesburg ... people are celebrating yoga day all across the world."

Thanking Prime Minister Modi for selecting Dehradun to host the main event, Uttarakhand Chief Minister Trivendra Singh Rawat said the move would also give a boost to tourism in the state.

The Prime Minister participated in the Yoga Day celebrations at Rajpath in New Delhi in 2015, the Capitol Complex in Chandigarh in 2016 and at the Ramabai Ambedkar Sabha Sthal in Lucknow in 2017.

In December 2014, based on a request from Modi, the United Nations General Assembly declared June 21 as the International Day of Yoga.