SEOUL — President Trump has the unwavering support of South Korea’s leftist Democratic, or Minju, party in his quest for the Nobel Peace Prize.

Mr. Trump, while meeting with Prime Minister Netanyahu at the White House, assessed the odds of his winning the prize, remarking, “I deserve the Nobel, but they will never give it to me.” Later, though, a member of Korea’s national assembly, Park Sun-won, disclosed that he had nominated the president for the prize for his “efforts toward North Korea’s denuclearization and his contributions to peace on the Korean peninsula.”

The Minju, in a formal statement, broadened the argument for awarding Mr. Trump the prize by saying he “would lead the peace initiatives on the Korean Peninsula and Northeast Asia by bringing an early end to Russia’s invasion of Ukraine and negotiations with North Korea on the nuclear issue.”

Closer to home, Mr. Park is believed to have urged the nomination of Mr. Trump for the Nobel as a way to win his support for the party’s drive to oust Korea’s conservative president, Yoon Seok-yul. After entering Mr. Trump’s name, he met the top American diplomat here, Joseph Yun, charge d’affaires of the American embassy, to inform him of the nomination.  With Mr. Park was a noted Minju adviser and advocate of reconciliation with North Korea, Moon Chung-in, who is believed to have suggested the party push Mr. Trump for the Nobel to get in his good graces. 

At the same time, the country’s impeached president, Mr. Yoon, faced hearings before the constitutional court on whether to approve his impeachment and ouster as president. It was the Minju, which has considerably more seats in the assembly than Mr. Moon’s conservative People Power Party, that spearheaded the motion to impeach him after voting down his martial law decree in December.

Korea’s biggest-selling newspaper, Chosun Ilbo, said the nomination of Mr. Trump for the Nobel “appears to reflect the intentions” of the party leader, Lee Jae-myung — whom Mr. Yoon defeated by a narrow margin in the 2022 presidential election — to run again.  

Conservatives denounced the nomination as a ploy to win Washington’s support for their Minju foe while Mr. Yoon, now in jail on a charge of “insurrection” for his “coup” against the state, fights for his political survival. Korea’s “democracy constitution” calls for a presidential election 60 days after the ouster of an impeached president.

Angling for America’s blessing of a change in the top echelons of South Korean leadership, the Minju portrays Mr. Trump as an advocate of reconciliation with North Korea’s leader, Kim Jong-un, whom he met three times during his first presidency. Having failed to persuade Mr. Kim to give up his nuclear program, Mr. Trump has expressed his desire to try again.

The spokesman for the Minju, Jo Seoung-hae, explaining Mr. Trump’s nomination for the Nobel, said the president “would continue to work for peace on the Korean Peninsula moving forward.” Minju leaders have joined the chorus of South Korean leftists calling for a “declaration of the end” of the Korean War, which wound up in an armistice, not a peace treaty, in July 1953.

Korean conservatives see such efforts as playing into Mr. Kim’s hands, and Americans in top positions, military and diplontic, agree. They believe he would go on refusing to give up his nukes while demanding withdrawal of America’s 28,500 troops and an end to the South’s American alliance. In this scenario, Mr. Trump might well consider pulling out the troops while demanding the South pay far more than the current $1.1 billion a year toward keeping them here.

Secretary Rubio, however, did not enhance the prospect for another Trump-Kim summit by lumping North Korea and Iran together as “rogue states.” North Korea, in its first comments on the new American administration, said it is “absurd and illogical … that the most depraved state in the world brands another country a rogue state.”

Mr. Trump’s chances for winning the Nobel do not rest solely on his efforts to bring peace to Korea.  A Republican member of Congress representing New York, Claudia Tenney, has already entered his name, just as anyone can do — not for his work on Korea but on the Middle East. She praised the president for brokering Israel’s treaty with Bahrain and the United Arab Emirates. 

Mr. Trump, she said on Fox, proved it was possible to reach agreements before “a resolution to the Israeli-Palestinian conflict.”