While meeting South Korean President Moon Jae-in on Sept. 21, President Trump said the two countries are making "a lot of progress" on a trade deal and imposing additional sanctions on North Korea, and praised Moon's use of the word "deplorable." (The Washington Post)

NEW YORK — On the agenda at the high-stakes bilateral meeting Thursday between President Trump and his South Korean counterpart Moon Jae-in: North Korea's nuclear arsenal, the bilateral trade deal and Hillary Clinton.

As he's shown repeatedly, Trump just can't seem to let go of his 2016 opponent, and Trump made a joke at her expense during a meeting with Moon on the sidelines of the United Nations General Assembly here.

An interpreter for Moon used the word “deplorable” in translating his remarks about the North's provocations, prompting Trump to cut in: “I'm happy you used the world 'deplorable.' I was very interested in that word.”

During the campaign, Clinton had told reporters that she put many of Trump's supporters in a “basket of deplorables” whose views were repugnant. That galvanized much of Trump's base, and the word “deplorable” was used as a rallying cry among some of his most ardent backers, who attached it to their Twitter handles and otherwise embraced the term.

As people in the room chuckled, Trump added in front of television cameras and reporters, “I promise, I did not tell them to use that word. That's been a very lucky word for me and many millions of people.”

Moon, waiting for a translator to repeat Trump's remarks, appeared uncomfortable but did not say anything. Clinton has been on a promotional tour for her new book about the campaign, “What Happened.”

Wrapping up the introductory remarks, Trump also bashed the bilateral trade pact signed by President Barack Obama in 2011 as “so bad for the United States and so good for Korea.” He has vowed to try to renegotiate the deal, raising concerns in Seoul and Washington that it could create a rift at a time when the two countries are trying to work together, and with Japan and China, to confront Pyongyang.