Prime Minister Justin Trudeau has joined the rising chorus of Western leaders alarmed by fires ravaging the Amazon rainforest, and said Friday that more needs to be done to protect the environment when the G7 summit takes place this weekend.

Trudeau is among a number of leaders putting Brazilian President Jair Bolsonaro in spotlight as more than 165,000 fires burn across the Amazon rainforest, a record number of them in Brazil.

According to Brazil's space research centre, INPE, which has been recording wildfires since 2013, more than 75,000 fires are burning in Brazil, which is a more than 80 per cent increase over the same period of 2018, the agency told Reuters.

"We need to act for the Amazon and act for our planet — our kids and grandkids are counting on us," Trudeau said in a tweet on Thursday.

The message came in response to a tweet posted by French President Emmanuel Macron.

"Our house is burning. Literally." Macron wrote. (Though the photo Macron tweeted does not depict the current fires, and the 20 per cent figure is overstated.)

I couldn’t agree more, <a href="https://twitter.com/EmmanuelMacron?ref_src=twsrc%5Etfw">@EmmanuelMacron</a>. We did lots of work to protect the environment at the <a href="https://twitter.com/hashtag/G7?src=hash&ref_src=twsrc%5Etfw">#G7</a> last year in Charlevoix, & we need to continue this weekend. We need to <a href="https://twitter.com/hashtag/ActForTheAmazon?src=hash&ref_src=twsrc%5Etfw">#ActForTheAmazon</a> & act for our planet — our kids & grandkids are counting on us. <a href="https://t.co/KwaR8Eevq5">https://t.co/KwaR8Eevq5</a> —@JustinTrudeau

This is an "international crisis" and members of the G7 need to prioritize the emergency and discuss it within the first two days of the upcoming summit, he tweeted.

Advisers to the G7 leaders are discussing concrete measures to be decided on during the summit this weekend in France, a French diplomatic source said on Friday.

"We are working at the advisers' level to take concrete initiatives on the Amazon as part of the G7," the source told Reuters. "Talks are ongoing," the source added.

The 45th G7 summit runs through the weekend in Biarritz, France. It brings together leaders of the world's most advanced economies, as well as representatives of the European Union, to discuss some of the most pressing issues facing the world.

Meanwhile, the Canadian government issued an advisory on Friday to Canadians travelling to Brazil, warning that air quality is affected throughout various regions, including São Paulo, and it could affect those suffering from respiratory problems.

This follows a state of emergency being declared in the state of Amazonas earlier this week.

International pressure mounts

The European Union is piling pressure on Bolsonaro over the fires raging in the Amazon basin, with Ireland and France saying they could block a trade deal with South America.

Bolsonaro has rejected what he calls foreign interference in domestic affairs in Brazil, where vast tracts of the Amazon rainforest are ablaze in what is known as the burning season.

The unprecedented surge in wildfires has occurred since Bolsonaro took office in January with a vow to develop the Amazon region for farming and mining, ignoring international concern over increased deforestation.

The Brazilian president — whose far-right policies have earned him the nickname "the Trump of the Tropics" — said on a Facebook Live session Wednesday, without any supporting evidence, that non-governmental organizations could be burning down the Amazon rainforest to bring shame on his government after he cut their funding.

Environmentalists have blamed deforestation for an increase in fires, and accuse the president of relaxing environmental protections on a vast carbon trap and climate driver that is crucial to combating global climate change.

Macron's office on Friday accused Bolsonaro of lying in playing down concerns about climate change at the G20 summit in Japan in June and that, in this light, France would oppose the deal struck between the EU and the Mercosur countries: Brazil, Argentina, Uruguay, Paraguay and Venezuela (which was suspended indefinitely in 2016).

Bolsonaro struck back at Macron's comment, saying that discussing the matter in a conference where Brazil is not invited to "evokes a misplaced colonialist mentality."

Irish Prime Minister Leo Varadkar said Friday that Dublin would vote against the deal unless Brazil acted to protect the rainforest.

"There is no way that Ireland will vote for the EU-Mercosur Free Trade Agreement if Brazil does not honour its environmental commitments," he said in a statement.

Varadkar said he was very concerned at the record levels of rainforest destruction, and that the Irish government would closely monitor Brazil's environmental actions in the two years leading up to the Mercosur deal being ratified.

And in the U.S., a senior White House official said on Friday that the U.S. government is deeply concerned about the wildfires.

"We are deeply concerned about the impact of the fires in the Amazon forest on the communities, biodiversity and natural resources of the region," the person said, declining to be named.

Brazilian army to protect Amazon

Under increasing international pressure, Bolsonaro said Friday he might send the military to battle the massive blazes.

"That's the plan," the Brazilian president said. He did not say when the armed forces would get involved but suggested that action could be imminent.

Earlier Friday, the head of the armed forces said the Brazilian army is ready to defend the Amazon rainforest.

"To the unwary who insist on safeguarding the purposes of the Brazilian Amazon, make no mistake, soldiers will always be alert and vigilant, ready to defend and repel any kind of threat," Edson Leal Pujol said in a speech during a Soldier's Day ceremony in Brasilia.

Brazilian President Jair Bolsonaro has said, without any supporting evidence, that non-governmental organizations could be burning down the Amazon rainforest to make his government look bad. (Getty Images)

Bolsonaro has previously described rainforest protections as an obstacle to economic development, sparring with critics who note that the Amazon produces vast amounts of oxygen and is considered crucial in efforts to combat climate change.

Small numbers of demonstrators gathered outside Brazilian diplomatic missions in Paris, London and Geneva to urge Brazil to do more to fight the fires.

Neighbouring Bolivia and Paraguay have also struggled to contain fires that swept through woods and fields and, in many cases, got out of control in high winds after being set by residents clearing land for farming. About 7,500 square kilometres of land has been affected in Bolivia, according to Defence Minister Javier Zavaleta.

On Friday, a B747-400 Supertanker arrived in Bolivia to help with the firefighting effort. The U.S.-based aircraft can carry nearly 76,000 litres of retardant, a substance used to stop fires.

Some 370 square kilometres have burned in northern Paraguay, near the borders with Brazil and Bolivia, said Joaquin Roa, a Paraguayan state emergency official. He said the situation has stabilized.