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.

France on Saturday banned the breeding in captivity of dolphins and killer whales under tighter rules that campaigners hope will eventually herald the end of shows involving the animals.

For the first time since Donald Trump's ascent to the White House, UN negotiators gather next week to draft rules to take forward the climate-rescue Paris Agreement he has threatened to abandon.

The South Pacific island nation of Vanuatu began assessing the damage Saturday after being pounded by destructive winds from Cyclone Donna which brought down houses and buildings.

The storm was upgraded late in the day to a category four severe tropical cyclone by the Vanuatu Meteorological Service which warned "damaging gale to destructive storm force winds" would continue to hit Torba province.

As UN negotiators meet in Bonn to thrash out rules for implementing the climate-rescue Paris Agreement, the stakes have never been higher.