Imran Khan, who was in Riyadh to meet the Saudi authorities before leaving for the US, was stopped by the Saudi Crown Prince from using a commercial flight to travel.
"You are our special guest and you would be going to the US on my special aircraft," Saudi Crown Prince Muhammad Bin Salman told the Pakistan Premier.
Imran Khan was received by Pakistan's Permanent representative to the UN, Maleeha Lodhi, Pakistan Ambassador to the US, Asad Majeed Khan, and other officials in New York.
According to Lodhi, Imran Khan on arrival has launched his "mission Kashmir for Pakistan" to try and draw the world's attention towards Kashmir.
This is Imran Khan's first General Assembly visit and "he will be the voice of the Kashmiri people at the UN," Lodhi said.
Imran Khan is staying at New York's Roosevelt Hotel, which is partially owned by the PIA.
This's where most Pakistani leaders stayed till September 2008, when then President Asif Ali Zardari and then Prime Minister Nawaz Sharif abandoned it for grander hotels like Waldorf Astoria, which cost at least 20 times more than the Roosevelt, Dawn reported.
Imran Khan arrived in New York during the weekend, which gives him the time to consult Pakistani diplomats and prominent members of the Pakistani-American community before meeting world leaders.
On Monday, his first informal engagement is breakfast with British Prime Minister Boris Johnson.
As always, the Pakistani Prime Minister's first official engagement at the UN is with the Chinese representative, and on Monday, Imran Khan will meet Chinese Vice President Wang Qishan.
At around 1 a.m. (Pakistan time) on Monday, Imran Khan meets US President Donald Trump, which could be the first of the two meetings the two are expected to have during the UN session. This would also be President Trump's second meeting with Imran Khan in less than 24 hours.
President Trump is scheduled to address a joint rally with Indian Prime Minister Narendra Modi at Houston, Texas, on September 22, hours before he meets the Pakistani Prime Minister. President Trump and PM Modi are expected to have a separate meeting before or after the rally, focusing on India-Pakistan relations.
Most world leaders will be in New York on Monday, to participate in the general debate, which begins on Tuesday.
Both Pakistani and Indian Prime Ministers are scheduled to address the UN General Assembly on September 27. PM Modi will speak first, on Friday morning, while Prime Minister Khan will speak later in the afternoon.
Prime Minister Khan has already announced that he will highlight the Kashmir issue in his address.
President Trump's recent comments on the Kashmir dispute have triggered speculations about an indirect dialogue between the two South Asian neighbours during the UNGA, with Washington playing the role of a facilitator, Dawn said.
Trump's expected meetings with both Indian and Pakistani Prime Ministers, before and during the UNGA, have enhanced the possibility that he may use this occasion to discuss the situation in Kashmir.
On Thursday, UN Secretary General Antonio Guterres said he would raise the Kashmir issue during his discussions with various leaders attending the 74th UNGA.
Imran Khan will also co-host a meeting at the UN with Turkey's President Recep Tayyip Erdogan on Countering Hate Speech.
A trilateral summit is also planned with Malaysia and Turkey.
He will address the UNGA on three more occasions at the Climate Change Summit, Summit on Universal Health Care and Financing for Development.
Outside the UN, Imran Khan will address the Asia Society and the Council on Foreign Relations, New York.
( With inputs from IANS )