NORAD Tracks Santa Operation Center on Peterson Air Force Base.

For decades, the Canadian and American defense agency NORAD has provided updates on Santa Claus's international gift delivery route, but this year, for the first time, US astronauts lent a hand.

"We have obtained visual confirmation that Santa is currently traveling south over India," Andrew Morgan said at 1700 GMT via a video link as he floated at zero gravity in the International Space Station.

The North American Aerospace Defense Command (NORAD) said that the ISS was traveling at 17,000 miles (27,000 kilometers) an hour, 250 miles above Earth -- providing "a great vantage point to spot Santa on his annual journey around the world."

A pen rests on the playbook for volunteers who will be taking calls from around the globe in the NORAD Tracks Santa center.

"NORAD appreciates the support of Colonel Morgan and the ISS team," it added.

The agency reported that Santa and his reindeer were approaching Punta Arenas, Chile at 0048 GMT Wednesday and had already delivered more than 4.3 billion gifts. They had taken off from the North Pole at 0930 GMT Tuesday.

NORAD has been tracking Santa since 1955 when a girl dialed a misprinted phone number from a department store advertisement in the local newspaper, believing she was calling Santa.

The number rang into the Air Defense Command Operation Center, where an officer was quick to realize the mistake and assured her he was Santa.

Each year since, NORAD has reported Santa's location to millions across the globe, with noradsanta.org this year live-tracking his present-filled sleigh pulled by nine reindeer.

Monitors are illuminated in the NORAD Tracks Santa center at Peterson Air Force Base.

Today, 1,500 volunteers help the military answer calls and emails from children.

US first lady Melania Trump joined the effort, listening to several children from across the United States tick off items on their Christmas lists.

She reminded them to put out milk and cookies for Santa.

The US Department of Agriculture said that "Mr S. Nicholas Claus" and his reindeer had been granted a special movement permit to enter the country and were "fit for landing on rooftops."

Agence France-Presse