Bollywood's celebrated filmmaker Karan Johar on Sunday announced he feels "enormously blessed" to have become a father to twins via surrogacy. Celebrities like actress Priyanka Chopra and choreographer-filmmaker Farah Khan congratulated him on the "happy" news.

The daughter has been named Roohi -- a rearrangement of Karan's mother's name Hiroo, and the son has been christened Yash -- after Karan's late father.

Karan, 44, said: "I am ecstatic to share with you all the two most wonderful additions to my life, my children and lifelines: Roohi and Yash. I feel enormously blessed to be a parent to these pieces of my heart who were welcomed into this world with the help of the marvels of medical science."

Best known for directing films like "Kuch Kuch Hota Hai" and "Kabhi Khushi Kabhie Gham...", Karan is still single.

He says parenthood is "an emotional yet well thought out decision" he has taken after considering all the responsibilities and duties that come with being one.

"In order to arrive at this decision, I have prepared myself mentally, physically, emotionally and logistically to ensure that my children get all the unconditional love, care and attention from me and mine."

"I have submitted to the fact that my children are my world and priority."

In his book "An Unsuitable Boy", Karan not just opened up about his sexuality -- albeit in a veiled manner -- but also expressed a desire to adopt a child or opt for surrogacy.

The filmmaker, who keeps travelling around the world and is known for his knack of making romantic dramas, understands that having children would mean that "work, travels and social commitments would have to take a back seat".

Karan also extended gratefulness to the surrogate who fulfilled his "lifelong dream and provided a warm, loving and nurturing environment to my children before bringing them into this world".

"She will always remain in my prayers."

Karan also extended gratitude to IVF specialist Jatin Shah, who was also instrumental in the successful birth of superstar Shah Rukh Khan and his wife Gauri's son AbRam through surrogacy.

Actors Alia Bhatt, Varun Dhawan and Sidharth Malhotra are thrilled with the new additions to the family of Karan, who launched their acting career in 2012 with his directorial "Student of the Year".

"Finally, I can say I have a younger brother and sister! So happy. So much love to give. Bursting with joy," Alia tweeted.

Sidharth also wrote: "So happy you took this decision Karan! It's a full house now. You will be an amazing father, love to your new big family."

Varun said: "Karan, you are the best human being I know and I'm sure you will make the best dad."

Congratulating the new father, actress Priyanka Chopra wrote: "So happy for you. May Yash and Roohi always have a beautiful healthy life. Much love always."

Farah, who has triplets with husband Shirish Kunder through In Vitro Fertilisation (IVF), is glad Karan finally took her advice seriously.

"Best thing to happen to you and they'll be the youngest people you hang out with, so all's good," said Farah, who had children at the age of 43.

While National Award-winning filmmaker Hansal Mehta welcomed Karan to fatherhood, actor Tusshar Kapoor, who became a single parent to Laksshaya Kapoor via surrogacy in 2016, said Karan deserved "these little blessings".

Actress Preity Zinta tweeted: "So happy for you and Hiroo aunty. I'm sure Yash and Roohi will bring light and happiness to your lives".

Director Sujoy Ghosh loved the names of the little ones and said: "As one tagline once said 'It's all about loving your parents'."

Filmmaker-host Sajid Khan also congratulated the Dharma Productions head honcho and tweeted: "Like you had said on my show 'Dharma needs an heir.' Now Dharma has...love their names."

Actress Sonakshi Sinha believes Karan will be the "best daddy and spoil them silly".