Hadi Nili, external from the BBC Persian service is outside the White House with anti-climate change demonstrators.

They want Trump and other guests at the Rose Garden to hear their noisy disapproval.

You may want to turn down your volume for this...

The BBC's Deirdre Finnerty is at the White House, where Trump was due to make his announcement 20 minutes ago.

Former Obama adviser Brian Deese points out that the earliest the US is likely to formally exit the Paris agreement will be just days before the 2020 presidential election, which would thrust climate to the forefront of Trump's re-election campaign.

The most prominent advocate of leaving was reportedly Steve Bannon, whom Trump critics have claimed is the real power in the Oval Office.

Environmentalist organisation the Sierra Club has mocked Trump on Twitter.

Astronaut Mark Kelly, who is married to Democrat former congresswoman Gabby Giffords, offers his unique perspective.

The US and China are the two biggest greenhouse gas emitters - but who are the other big culprits?

Here's a simple graph breaking it down:

Kentucky Senator Rand Paul, who supports US withdrawal, tells CNN there is much "alarmism" around climate change.

The accord is not fair because China can go on polluting while the US has to cut back on output, costing American jobs, he argues.

There is much uncertainty whether the planet is warming or cooling, he adds.

"The modelling doesn't add up."

Foreign policy adviser and speechwriter to former president Barack Obama, Ben Rhodes, has posted his excoriating thoughts online.

The BBC's Barbara Plett Usher , externalis in the White House Rose Garden awaiting Trump's announcement.

She has just sent us this image.

The current temperature in Washington DC is a balmy 82F (28C).

The LA Times editorial board writes that withdrawing from the agreement would "send a troubling signal that the nationalists on his [Trump's] team have won out over the realists, which means the administration is becoming more inwardly focused as the world is growing more globally connected".

Trump's daughter Ivanka and her husband Jared had reportedly been pushing for America to remain in the Paris agreement. Secretary of State - and ex-ExxonMobil chief executive - Rex Tillerson also advocated for the US to remain in.

"The polar ice sheets are already shrinking, glaciers are melting, ocean levels are rising, storms have intensified, and droughts and downpours have become stronger and more erratic as species become stressed and trees that once thrived in places like the Sierra Nevada die by the millions, external.

"The world needs to go in one direction, and Trump wants to point the United States the wrong way," the newspaper writes, external.

President Trump's trailing of his decision on whether the US will stay in the Paris Agreement has exasperated some in Germany.

"Out, in, out, in. Donald Trump’s approach to the climate agreement is cynical," the weekly Der Spiegel says, "because actually the decision appears to have already been made."

"The billionaire will withdraw the US from the treaty... and, after all, given what we know about the president in this respect, that would not be very surprising," it adds.

The tabloid Bild, external was hopeful that Trump's daughter Ivanka could still change his mind about pulling out, saying she and her husband Jared Kushner are "vehemently against an exit".

While Germany remains staunchly allied to the West, Trump should not "habour any illusion" it has no other options, the Frankfurter Allgemeine Zeitung warns., external

"In questions of climate and trade policy, Germany is busy forging new alliances. With China and India."

China’s Global Times has issued a particularly strong editorial, saying the US would "set a bad example" to the world if it chose to leave. "It will become the biggest waste of its diplomatic resources in recent years. It will show the world clearly that the US is selfish and irresponsible and weaken the US leadership of the world."

China's Shenzhen TV stresses that "whatever Mr Trump’s words or deeds have done to draw criticism, China reaffirms that it will continue with the EU to show its support" for the Paris agreement.

"China will continue to implement promises made in the Paris Agreement, to move towards the 2030 goal step by step steadfastly," Premier Li Keqiang said in Berlin today, at a news conference with German Chancellor Angela Merkel.

(via BBCMonitoring)

California Governor Jerry Brown tells the BBC that his state will continue to negotiate with the international community in order to alleviate climate change.

He says that California will work with Chinese President Xi Jinping.

New York media report that Governor Andrew Cuomo will announce his intention later today to uphold the state's commitment to the Paris agreement.

Politico, CNN and the Associated Press news agency have also just reported that Trump will pull out of the Paris accord at the top of this hour.

Russian President Vladimir Putin's spokesman Dmitry Peskov says it will be harder to implement a deal without Washington.

"You know that President Putin was in Paris and signed this convention. Russia attaches great significance to it. However, obviously, the efficiency of the implementation of this convention is likely to become more difficult without key parties, but there is currently no alternative," he told RIA Novosti news agency.

Image source, European Photopress Agency

"The United States is getting out of the Paris agreement," White House energy policy adviser Michael Catanzaro just confirmed in a conference call with congressional staffers.

Trump, Catanzaro said, "will be open to and will immediately be looking for a better deal", the Daily Beast reports, external.

"We will initiate the process, which, all told, takes four years in total. But we’re going to make very clear to the world that we’re not going to be abiding by what the previous administration agreed to."

Image source, Liberation

French newspapers argue that recent tension between President Trump and Europe over Nato and climate change could yield some unexpected opportunities - for the EU. "The virulence of the US president against the backdrop of Brexit could paradoxically prompt the Franco-German duo to accelerate to finally get the EU out of its crisis," Liberation says, external. Similarly, Le Figaro argues, external the US president's attitude "could awaken a sleeping Europe", but that such awakening would be “brutal”. Le Monde, external notes that full withdrawal from the agreement could take four years, which means it would take effect during America’s next presidential election, in November 2020.

Politico reports that prominent opponents of the Paris agreement will be in the Rose Garden for Trump's announcement in under an hour's time.

Thomas Pyle, president of the fossil fuel-backed American Energy Alliance; Myron Ebell of the Competitive Enterprise Institute, a libertarian think tank; and experts from the Heritage Foundation, a conservative think thank, are all due to attend.

Given the guest list, speculation is building that Trump will indeed pull out.

Oklahoma Senator Jim Inhofe, who famously brought a snowball to the Senate floor in an attempt to disprove climate change, has written an op-ed calling for America's withdrawal from the Paris agreement.

He says the agreement was "a false promise from the beginning", calling the greenhouse gas reduction goals "unattainable".

"We must do everything in our power to advance the development of domestic energy to lead the world away from dependence on energy-rich regimes like Iran and Russia," he writes.

"Our abundance is a competitive advantage that we can share freely with our allies," his letter concludes.

From all corners of the globe, appeals to the president to rethink his rumoured decision to leave the Paris agreement have flooded in ahead of today's press conference.

UN Secretary General Antonio Guterres told the BBC Trump's support for the deal was crucial to its success, while China, Russia and Germany all reaffirmed their commitment in the face of a possible US withdrawal.

Others took to social media to beg the leader of the world's biggest economy to stay committed to the accord.

We'll find out soon whether pleas by the likes of Katy Perry and others have fallen on deaf ears...