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.

It's named after a Nordic god and drills deep into the heart of a volcano: "Thor" is a rig that symbolises Iceland's leading-edge efforts to produce powerful clean energy.

If successful, the experimental project could produce up to 10 times more energy than an existing conventional gas or oil well, by generating electricity from the heat stored inside the earth: in this case, volcanic areas. 

A giant coal-fired power plant approved by Bangladesh could drastically worsen air pollution for millions and cause the early deaths of 6,000 people over its lifetime, Greenpeace said Friday.

A major dust storm engulfed northern China and Beijing on Thursday, prompting authorities to cancel dozens of flights and urge children and the elderly to stay indoors.