SINGAPORE (AP) — Miles from Washington, staring down a momentous meeting with a North Korean autocrat, President Donald Trump had plenty of other things on his mind, too.

On the eve of his big summit with Kim Jong Un, Trump on Monday piled on more tweets in his escalating trade war with Canada and sent out a top official to bash news reporting suggesting Trump's summit preparations could have been hindered by the lack of a top science adviser. The characteristic displays of pique were a potential distraction from the summit that Trump has hoped to make a legacy-defining moment and that aides and political allies have seen as a welcome break from the Russia investigation and other domestic woes.

Trump had tweeted over the weekend: "I am on my way to Singapore where we have a chance to achieve a truly wonderful result for North Korea and the World." While aboard Air Force One, the president also tweeted out a plug for South Carolina Gov. Henry McMaster ahead of the state's Tuesday primary.

The nuclear summit carries not just high stakes for the Korean Peninsula and the fate of millions, but also Trump's own political fortunes. Trump's self-proclaimed negotiating skills formed the basis of his public persona even before it became the core of his political identity, when he was elected promising that he alone could fix the nation's ills.

The political consequences of the summit have not been lost on Trump or his allies. Surrogates have been hitting television for weeks celebrating the very notion of a meeting between Trump and Kim as a foreign policy success, and Trump's campaign has documented the summit progress in weekly emails to supporters.

Trump aides long ago gave up trying to focus the easily distracted president on one thing at a time, as he tweets at random about the NFL, Russia, Democrats and a raft of other grievances.

Instead, they hoped the president — who billed himself as a dealmaker long before he entered politics — could achieve enough in Singapore to frame the meeting as a win that helps bolster the president against critics and supports his party going into the midterm elections.

In a short period Monday, Trump lobbed five tweets about trade and his conflict with Canadian Prime Minister Justin Trudeau, drawing harsh condemnation from Canada and other allies. In one he offered: "Sorry, we cannot let our friends, or enemies, take advantage of us on Trade anymore. We must put the American worker first!"

On the summit, Trump tweeted just once, saying there was "excitement in the air."

Later in the day, Secretary of State Mike Pompeo briefed reporters on summit planning, taking time to specifically criticize a New York Times report that said Trump's team lacked a White House science adviser going into the denuclearization talks. The rebuke was in keeping with Trump's aggressive broadsides against the media.

Pompeo said "any suggestion that the United States somehow lacks the technical expertise across government, or lacks it on the ground here in Singapore, is mistaken." New York Times spokeswoman Danielle Rhoades Ha said the paper never said the administration lacked experts, but "reported on long-standing scientific roles that do not exist in the current administration and the overall marginalization of science and scientific expertise in shaping federal policy."

Trump has enjoyed all the attention attached to his unprecedented sit-down with Kim, basking in suggestions that he might be a candidate for a Nobel Peace Prize. But in recent days he began to lower expectations that he can deliver a nuclear deal in one swoop.