But where does the relationship between the US and the UN stand as he prepares to make his second presidential appearance at the UN podium next week?
The US has repeatedly complained about paying 22% of the UN’s regular budget.
The percentage is reached using a formula and based on the size of the country’s economy.
Trump sparked fears that he would slash US payments to the UN’s peacekeeping budget by roughly $1bn last year.
Many credit his ambassador to the UN, Nikki Haley, with toning down his plans to make slash-and-burn cuts.
Additionally, UN Secretary General Antonio Guterres announced a reorganisation of its peacekeeping department and plans to streamline the management structure in July, which appear to be keeping Trump at bay.
“I think Haley and Guterres will be able to tell Trump – with a lot of caveats and compromises – that they have pushed through development reforms as promised when Trump was here last year,” says UN expert Richard Gowan, a senior fellow at UN university who has also worked at New York and Columbia universities.
“I doubt Trump has any idea of the detail of what those reforms are, but he can call that a win,” Gowan told DPA.
Guterres has been successful in developing a relationship with Trump.
After an Oval Office meeting in May, Trump tweeted a picture of himself, giving a thumbs up, with Guterres and Haley, saying the UN chief was “working hard to ‘Make the United Nations Great Again.’”
And there have been successes.
Peter Yeo, head of the Better World Campaign, an independent organisation that lobbies for US-UN co-operation, notes that Haley’s team has had successes negotiating on issues at the UN, including North Korea sanctions.
However, while Trump has taken his eye off the UN and the budget as a whole, there are still several specific UN agencies and agreements set to take hits because they don’t align with White House philosophies.
On migration, Washington baulks at signing the Global Compact for Migration, which UN countries finalised in July as the first common international approach on this issue.
And Trump caused controversy by pulling out of the Paris climate agreement, which was negotiated under the auspices of the UN, and the Iran nuclear deal, which was endorsed by a resolution of the UN Security Council.
The US also hasn’t given up on its most controversial criticism of the UN – that the world forum is biased against Israel.
Anti-Israel bias was the justification given for pulling out of the UN’s Human Rights Council and the Unesco world heritage site foundation.
And sometimes it is about money, but not UN finances.
The Trump administration has made it clear it expects a return on investment, a point it has made loudly when individual countries it supports make decisions the US dislikes at the world body.
For example, after the US decided to recognise Jerusalem as the capital of Israel, the UN’s 193-member General Assembly overwhelmingly voted to criticise the move.
Trump threatened to cut financial support to countries that voted against the US, with Haley complaining that the US is “asked to pay for the privilege of being disrespected” at the UN.
“The ‘we pay the bills’ rhetoric doesn’t help,” says Yeo.
“It can always feel a bit like the end of the world” when the US falls out with the UN, Gowan says, but this isn’t the first time.
The US came close to losing its voting rights in the General Assembly under Bill Clinton for failing to pay its dues.
And the diplomatic atmosphere surrounding Iraq in 2003 was “utterly dreadful,” he says.
The US rebelling against the UN is not strange, but what Gowan sees as “pretty unusual and disturbing” right now is the US behaviour towards the UN, paired with Trump’s overarching attitude to multilateralism.
Trump has criticised Nato repeatedly, and the US president said last month he would consider withdrawing from the World Trade Organisation “if they don’t shape up.”
Guterres said in a recent interview that the US is losing its “soft power” by stepping back from its leading role.
This move could be dangerous as there “is no way to solve most of the problems in the world without” the US, he told The Atlantic magazine.
The outgoing president of the UN’s 193-member parliament, the General Assembly, echoed him, saying a shift from a world dominated by a single power is taking place.
Without explicitly mentioning the US, Miroslav Lajcak said this shift was happening unchecked and there have been violations of international agreements, norms and rules “without punishment or without adequate reaction, which can trigger others to do the same.”
“We really have to raise our voice to demand that everyone respects the rules – and it doesn’t matter how big or small the country is – so we don’t find ourselves in a world we don’t like,” Lajcak said.