Pope Francis on Monday (November 28) greeted British physicist Stephen Hawking who was attending a meeting of scientists at the Vatican.

The pope stopped and placed his hand on the shoulder of Hawking who was seated in his special chair.

Scientists were attending the convention entitled, "Science and Sustainability: Impacts of Scientific Knowledge and Technology on Human Society and its Environment."

During the meeting Pope Francis urged national leaders to implement global environmental agreements without delay, a message that looked to be squarely aimed at U.S. President-elect Donald Trump.

It was the pope's strongest speech on the environment since the election of Trump, who has threatened to pull out of the 2015 Paris Agreement on climate change. — Reuters