"I'd never guessed President Xi's hand was so warm and soft," Lang Lang, 33, the Chinese superstar pianist, told me over the phone on Saturday morning, half an hour after he shook hands with Xi at United Nations headquarters in New York.

Lang got up at 7 am. "I was so excited that I barely slept," he said. He was accompanied by his mom, who went to bed way earlier than she usually does. "She dressed up this morning."

In 2013, Secretary-General Ban Ki-moon designated Lang a United Nations Messenger of Peace with a focus on global education. He is the youngest of the 13 messengers, whose ranks include Leonardo Di Caprio, Michael Douglas and Yo-Yo Ma.

Lang's job on Saturday was to welcome the Chinese president for his first appearance at the UN.

Lang and his mom arrived early. Joined by Mogens Lykketoft, the president of the General Assembly, they waited in a meeting room.

In the media room overlooking the General Assembly Hall where the Sustainable Development Summit was unfolding, my colleagues and I also were waiting for the president. (When we talk off the record, and in Chinese, we mostly call him "Uncle Xi". Almost every Chinese does.) He was going to speak at the summit.

Among all those telescopic cameras, an Asian-looking lady taking pictures with her iPhone stood out.

"Chinese?" I asked.

"Yes," she replied.

Of course, we started to talk in Chinese.

She has worked at the UN for more than a decade as an interpreter. There are a couple of hundreds of Chinese nationals working at the UN, she told me.

She was supposed to be working in another meeting at that moment, but switched her shift so she could sneak into the media room to catch a glimpse of the president. "It's a pretty big thing for us Chinese working here," she said.

We waited.

Lang and his mom were among the first people who met Xi. He shook hands with Lang and then with his mother, Zhou Xiulan.

"His hand is like a pianist's hand," Lang said. What surprised him even more was how easygoing the Chinese leader was.

"He's the most gentle and kind top leader I've met. Like a real uncle," Lang said, though they hardly talked. "I felt close to him. And it's almost Mid-Autumn Festival."

Lang has met a lot of top leaders in China and around the world. He spoke like an excited fan.

And when I saw the president, albeit from a bird's-eye view about 150 feet away, I felt the same. It's a weird feeling of closeness when you see a world leader that you've seen only on TV, in real life.

Xi walked in and sat down, put on the headphones and listened to the other heads of state speak. He looked a little tired.

The UN lady took dozens of photos of him. I did too with my iPhone and even a distant selfie with him in the frame.

When he walked toward the podium, Lang waved from his seat and cheered, "Go President Xi!"

"He looked at me, and smiled," Lang laughed.

"When he's done. A line was waiting for him," Lang told me. "Cuban President Raul Castro, he was waiting in the line."

It's a proud day.

Contact the writer at hezijiang@chinadailyusa.com