Their partnership will be a greater force for peace and harmony in the world.
Once deeply critical of the United Nations - right down to its iconic emerald marble - Trump as President has achieved his principal diplomatic wins at the body's Security Council, which has passed waves of sanctions on North Korea. "The United Nations has fallen short, and he wants to motivate them", said Secretary of State Rex Tillerson.
Trump has also been critical of the United Nations and has promised to cut the U.S. contribution to its budget, which is the largest. It will be the first time world leaders will be in the same room and able to take the measure of Trump.
He said the speech would also be an opportunity for Mr Trump to put forward the US's position on the Iran nuclear deal, coming just two weeks before the president must next report to Congress on whether Tehran is still in compliance with the agreement.
In a phone call the two men discussed "North Korea's continued defiance of the global community and its efforts to destabilise Northeast Asia", the White House said.
The president has a packed scheduled for the four-day event in NY, including his hotly anticipated speech to the assembled delegations Tuesday.
Asked if the US would stay in that deal, Trumped answered only "you'll see very soon".
Trump is to meet with the head of the Palestinian Authority later in the week, but the White House has played down prospects for a breakthrough.
President Trump is waking up at home in NY this morning.
"They're going to find out we are going to be solid, we're going to be strong", Haley said.
Haley on Friday pointed to the more than 120 countries that back the US-drafted political declaration on United Nations reform as a "miraculous number", showing there is support for a "massive reform package" led by Guterres. "But the next morning he may send out a bunch of tweets attacking the U.N". And right before he started talking about what a disappointment the United Nations has been, Trump plugged his building across the street. The leaders of South Korea and Japan will join Mr. Trump for lunch, where North Korean nuclear weapon and long-range missile programs will be the main topic.
Mending fences - as a candidate President Trump called the United Nations weak - incompetent - not a friend of democracy.
Neither presidents from China nor Russian Federation will be at the United Nations this week.
"The secretary general will emphasise the need to streamline the United Nations bureaucracy, and the Trump administration will cheer him on", he said. And a late addition to the hundreds of official meetings and side events during the ministerial week is a high-level session Monday on the devastation caused by Hurricane Irma.
Trump also planned to hold separate talks Monday with Israeli Prime Minister Benjamin Netanyahu and French President Emmanuel Macron.