UPDATE (8:30 A.M. EST):
President Donald Trump touched down in Singapore on Sunday evening, 36 hours before his highly anticipated summit with North Korean leader Kim Jong Un is set to kick off.
Trump arrived on Air Force One at Singapore's Paya Lebar Air Base at 8:21 p.m. local time, where he was greeted by Singapore's Foreign Minister Vivian Balakrishnan. Kim arrived at Singapore's commercial airport on an Air China Boeing 747 just more than five hours earlier.
Trump, asked by reporters as he arrived in Singapore how feels about the summit, said "very good" before climbing into his limousine and heading to the hotel.
The US President flew to Singapore from Canada, where he participated in an especially contentious G7 summit that came after he triggered a trade dispute with several of the US' closest allies.
Kim Jong Un, North Korea's leader, arrived in Singapore earlier.
North Korean leader Kim Jong Un met with Singapore Prime Minister Lee Hsien Loong on Sunday, hours after arriving in Singapore and ahead of an historic summit with US President Donald Trump. Lee will have a separate meeting with Trump on Monday.
Kim was greeted at Singapore's Changi airport by Singapore's Minister for Foreign Affairs, Vivian Balakrishnan.
According to images released by the Singaporean government, Kim arrived on an Air China plane. Accompanying him was Kim Yong Chol, who earlier this monthmet with President Trump to hand deliver a letter from Kim.
Trump declared that the young dictator had a "one-time shot" to bring his country in from the cold with the summit.
Kim arrived at the St Regis Hotel Sunday, where around 20 North Korean guards -- distinguishable by red loyalty badges -- had earlier taken up positions, some on upper floors overlooking the hotel's lobby.
Together with Singaporean police officers and hotel staff they created a human shield around the entrance blocking Kim's arrival from view. Strict security saw hotel guests banned from holding phones or bags and told to remain seated.
When he arrived at around 3:40 p.m. local time (3:40 p.m. ET), Kim went straight to the hotel's elevators without acknowledging the crowd.
A procession of North Korean officials -- including his younger sister Kim Yo Jong -- arrived shortly afterward.
Trump on opportunity
While Trump spoke positively about his upcoming meeting with Kim, he was vague on the details of what they might actually achieve.
"I feel that Kim Jong Un wants to do something great for his people," Trump told reporters at a press conference in Canada before departing the G7 summit. "And he has that opportunity, and he won't have that opportunity again."
Trump also speculated that the summit might not work out. He would know, he told reporters, very early on in meeting Kim, if it would.
"I think within the first minute I'll know," Trump said. "At a minimum, I do believe, at least we'll have met each other," Trump said, adding later that "hopefully, we will have liked each other."
US officials have established a contingency plan for a potential second day of discussions between Trump and Kim depending on the direction of their planned meeting on June 12.
The cost of the summit for Singapore was some $15 million, Singapore Prime Minister Lee told reporters Sunday at the media center the city-state had constructed to deal with the enormous international demand.
"It's our contribution to an international endeavor which is in our profound interest," Lee said.
A team of US officials had been in South Korea, traveling frequently to meet with North Korean officials in the demilitarized zone [DMZ] recently, to work on the substance of the talks.
Even as American officials including top diplomat Secretary of State Mike Pompeo say that North Korea is prepared to fully denuclearize, there are questions over what that entails for not just Pyongyang, but also Washington and Seoul.
Since Kim decided to reach out through diplomatic means to the South in January of this year, he has signaled that he is prepared to accept certain aspects of the US-South Korea military alliance.
In April, South Korean President Moon Jae-in said Kim was willing to give up US troops' removal from South Korea as a precondition for denuclearizing the Korean peninsula.
In March, Moon said Kim understood the South's stance on holding military drills with the US military, but last month suspended talks with the South because of annual air combat drills involving some 2,000 troops from the US and South Korea.
But questions remain over Kim's willingness to fully abandon his nuclear program, dismantle weapons and allow independent experts in to verify and inspect every site in the country that might be involved.
There is also the question of what will become of North Korea's short and medium-range ballistic missiles, which has been a great concern for North Korea's neighbors, including Japan.
Japanese Prime Minister Shinzo Abe flew to Washington last week to meet with Trump before the G7 to ensure Japan's interests weren't overlooked in the summit.
Regional allies are concerned that Washington will focus mainly on the threat to the US mainland and push North Korea on its intercontinental ballistic missiles, without also including the lesser threat to the US, but a threat nevertheless, to the region.