On Friday, leaders from the world’s biggest economies will meet at the G20 summit in Hamburg, Germany, where many of those public spats could be rekindled.
German Chancellor Angela Merkel has said she wants the summit to focus on key international issues such as climate change, free trade and an unfettered press — issues that push up against Trump’s positions and populist rhetoric.
Here’s a look at some key issues that may be discussed at the summit — and how Trump and G20 leaders have clashed over them.
All but three countries have signed the Paris Agreement, a landmark deal that asks every country to reduce their greenhouse emissions. In June, Trump pulled out of the agreement and joined Syria and Nicaragua in the small club of countries that have rejected the deal.
In a speech last week, Merkel spoke to Trump’s worldview without directly naming him. She said, “We cannot wait until every last person on Earth has been convinced of the scientific proof.”
Other G20 leaders haven’t been shy to voice their discontent with his decision, including France’s President Emmanuel Macron, Indian Prime Minister Narendra Modi, and Australian Prime Minister Malcolm Turnbull, who called Trump’s withdrawal “disappointing but not at all surprising.”
Trump has forged ahead with his tough-on-trade campaign promises.
In April, Trump announced he would stay in the deal but would negotiate its terms after speaking with his counterparts in Canada and Mexico.
Following the decision, Chinese President Xi Jinping said his country would “remain committed to promoting free trade and investment through opening up and say no to protectionism.”
Trump has criticized steel suppliers for cheating on steel prices. Experts fear a trade war could arise if Trump follows through with tariffs on those countries, which include, Canada, Mexico, Brazil the EU, Japan, and China.
But he seemed to back away from disregarding the alliance in June by formally reiterating the US’ commitment to the principle that an attack on one member is an attack on them all.
UK Prime Minister Theresa May called the ban “divisive and wrong.”
Trump has also doubled down on his promise to build a Mexican border wall, since vowing that Mexico will pay for it. Mexico says it won’t.
Trump has said that China isn’t doing enough to pressure the regime.
Washington and Beijing have also clashed over the plan to deploy an anti-missile system in South Korea, something Russia also opposes.
The US and Russia say their forces are in Syria to fight ISIS, with Russia allied alongside President Bashar al-Assad’s regime and the US working with groups that oppose both Assad and ISIS.
Tensions between Moscow and Washington have risen since the US launched an airstrike in Syria after Assad’s forces staged a deadly chemical attack.
Last month the US shot down a Syrian warplane, prompting Russia to shut down a communication channel between the two countries.