President Biden's special envoy for climate issues is counting on Pope Francis' support to get nations attending the next U.N. climate summit to adopt bold measures to mitigate climate change.

"The Holy Father has an enormous ability to convene people, to help generate energy" on climate change, John Kerry, the president's envoy for climate issues, told reporters following a private meeting with Pope Francis at the Vatican June 19.

"My hope is that he is going to engage and be one of the people focused on this moment, which I think is almost equivalent to Paris," he said, referring to the landmark 2015 U.N. climate summit in which 196 parties agreed to limit global temperature increase to 1.5 degrees Celsius above pre-industrial levels.

The United States withdrew from the agreement in 2017 before rejoining it in 2021.

Kerry said Pope Francis has "remarkable leverage" in drawing attention to climate change and that the pope has "constantly been an outspoken and engaged advocate" on climate issues.

He recalled a meeting of nearly 40 leaders of the world's major religions as well as top scientists at the Vatican in 2021 to call on world leaders to take seriously their obligation to curb emissions trends at that year's U.N. climate summit in Glasgow, Scotland.

"I think it might be helpful to try to rekindle some of those embers and start to generate the focus now" before the November summit in Dubai, United Arab Emirates, said Kerry.

Meeting the pope on the same day Antony Blinken, U.S. secretary of state, met with Chinese President Xi Jinping, Kerry said he spoke with the pope about the United States and China's roles in global emissions production.

The two "took note, together, of the fact that China and the United States represent about 40% of all emissions," and discussed the responsibilities of both nations to take steps forward in reducing their carbon footprint, he said.

China, Kerry said, "has an ability to have more of an impact than any other nation in the world" in reducing emissions.

Kerry said he "chatted" with the pope about the war in Ukraine thought it was not the focus of their conversation and said that the pope articulated "the degree to which (the war) is disturbing the ability to focus on other things at the same time," such as the climate crisis.

A practicing Catholic, Kerry said caring for the environment "goes to the heart of morality, of individual responsibility for your neighbors and for mother Earth."

He cited the influence of Pope Francis' 2015 encyclical "Laudato si', On Care for Our Common Home," in defining life in relationship to God, to neighbor and to the earth.

"Being Catholic involves finding ways to live that out, in my judgment," Kerry said, calling skepticism before issues of climate change on the part of Catholics "a mistake."