Countries at high risk of sea-level rise, drought and storms caused by global warming urged world leaders Wednesday to stay the course despite America's threatened exit from a U.N. climate pact.

A batch of centuries-old olive trees in southern Italy have been moved out of the way of a controversial new pipeline in a dead-of-night operation that required the deployment of dozens of police.

The dried-out oyster shells lie on a landscape parched and cracked by the sun.

U.S. Secretary of State Rex Tillerson warned the governments and peoples of the Arctic on Thursday that President Donald Trump will put America first when it comes to climate change.

Representatives from the eight nations with territory in the great white north and the indigenous peoples who make their homes there had come to Alaska looking for reassurance.

The collapse of a tunnel at the most contaminated nuclear waste site in the United States has raised safety concerns at such facilities described by some as ticking time bombs.

The first tropical storm of 2017 went down in the record books as the earliest named storm formation in the eastern Pacific Ocean, according to the National Hurricane Center.

The White House said Tuesday that Donald Trump will not decide on future U.S. participation in the Paris climate accord before he returns from a trip to the Middle East and Europe later this month.

"The president has been meeting with his team for quite a while on this matter and he will not be making an announcement regarding that agreement until after he returns from the G7," said Sean Spicer.

Climate negotiators return for talks in Bonn Tuesday under the cloud of Donald Trump's threats to pull America from the hard-fought Paris Agreement, as the president prepares to hold a special meeting to discuss US participation.

After months of uncertainty, the US president appeared closer to a decision on whether he intends to keep a campaign promise to withdraw Washington from the climate-rescue pact, whose practicalities are being haggled over during UN talks in Bonn.  

With heavy rains persisting and waters still rising over much of waterlogged eastern Canada, the nation's military on Sunday tripled the number of troops urgently working to evacuate thousands of residents.

Uncertainty over America's future in the climate-rescue Paris Agreement loomed large over UN talks that opened in Bonn Monday to work out the nuts and bolts of implementing the hard-fought international deal.