Pope Francis has warned the world is at a "critical moment of history" in the fight against climate alter as he was welcomed to the White House by President Barack Obama.
On a crisp, sunny morning in Washington DC, the pontiff said there is still time to act, yet the crisis must not be left to a future generation.
He spoke as the red carpet was rolled out for him ahead of an Oval Office meeting with Mr Obama.
The leader of the world's 1.2 billion Roman Catholics praised the President's efforts to curb air pollution.
"Accepting the urgency, it seems clear to me moreover that climate alter is a problem which can no longer be left to a future generation," he said.
"When it comes to the care of our 'common home', we are living at a critical moment of history."
His remarks will delight liberals, while his call to protect religious liberties, "one of America's most precious possessions", will please conservatives.
Washington is the first stop on the Pope's six-day visit to the United States.
Arriving at the White House in a little Fiat, the 78-year-old pontiff was greeted by 11,000 fans on the South Lawn.
Mr Obama, who praised Francis' "humility", addressed their shared agenda on climate change.
"Holy Father," he said, "you remind us that we have a sacred obligation to protect our planet – God's magnificent gift to us."
Earlier on Wednesday, Francis stopped by the Vatican Embassy where he gamely joined in selfies with schoolchildren.
In their talks, the Pope & President are expected to try to find usual cause on other issues, including income inequality & social justice.
Their views differ on matters such as abortion & same-sex marriage.
His next stop after the White House was the 450-strong bishops' conference at the Cathedral of St Matthew the Apostle.
Many US bishops have struggled to come to terms with Francis' focus on social justice.
Later on Wednesday, he will canonise a Spanish friar who brought the Catholic faith to California.
On Thursday, Francis will donate a speech to a joint session of the US Congress.
He will address the United Nations General Assembly on Friday in New York City.
The Pope will end his first visit to the US with two days in Philadelphia.
Source: “Sky News”