A prominent Hawaii activist apparently has been banned from South Korea and is now seeking answers.

Christine Ahn, who was born in South Korea and immigrated to the United States, made international headlines in 2015 when her Honolulu-based organization Women Cross DMZ rallied 30 women to cross the demilitarized zone between North and South Korea.

She has been an outspoken advocate of formally ending the Korean War, which was halted by an armistice in 1953 but never truly ended. Her activism has been at times controversial, with critics alleging that her efforts advance the North Korean regime’s interests.

On Oct. 30, Ahn was at Daniel K. Inouye International Airport getting ready to board an Asiana Airlines flight to South Korea, where she was was scheduled to give a keynote address at the International Youth Peace Forum in Gyeonggi province on Nov. 2. She also planned to meet with U.S. officials in the country.

“I gave them my passport to check in, they were inputting my TSA number and then something must have flashed on the monitor,” Ahn told the Honolulu Star-Advertiser. “(The ticketing agent) said, ‘Oh, excuse me, Miss Ahn,’ and then they went to the back, and then a more senior ticketing agent came to the front and explained to me that they called the (Republic of Korea) immigration authorities, and they were informed that they were not allowed to print a boarding pass, and I was not allowed to board the plane to Incheon.”

Amnesty International and Women Cross DMZ have posted an online petition calling on South Korean President Yoon Suk Yeol to lift the ban. The petition, which has gained more than 1,000 signatures, states, “We are outraged that Ahn — a respected Korean American peace activist — has been barred from traveling to South Korea without any reason or justification, which is a violation of her human rights.”

“I am extremely shocked and disappointed by this decision that is not even transparent. I have still not been given an explanation,” Ahn said. “I’ve tried to call multiple times to different numbers that I received from the South Korean National Assembly, and I was just passed on to from person to person. … I spoke to an immigration official at Incheon, and he asked me for my passport number. He obviously looked into it, and he did not give me any final decision on why I was denied entry. So this is a serious case.”

Ahn said she is in talks with U.S. diplomatic officials and lawmakers. Some officials in South Korea also have raised concerns about the apparent ban.

Ahn Young-wook, secretary general of the Gyeonggi Peace Education Center, said in a statement to media, “The International Youth Peace Forum, which is being held with the support of the Gyeonggi government, invited Women Cross DMZ’s founder Christine Ahn to deliver the keynote speech. We do not understand why she was not allowed to participate in a conference where the youth of South Korea and the world will gather to discuss peace on the Korean Peninsula and our world.”

“Women’s voices and perspectives are essential to ending war and promoting peace, so I am deeply disturbed that Christine Ahn has been prohibited from entering South Korea,” said Lee Jae Jung, a longtime member of South Korea’s Parliament who sits on its Foreign Affairs and Unification Committee. “The U.S.-ROK alliance must not just be a military alliance, but one that champions democracy, nurtures peace, and empowers women to lead the way in healing and reconciliation.”

The U.S. does not have direct diplomatic relations with North Korea. Ahn has at times been involved in “back channel” diplomacy with North Korea, engaging with officials and relaying messages behind the scenes. Though she has had a sometimes contentious relationship with American officials, some say they have come to find her relationships useful.

But Ahn’s activities also have made her the subject of intense scrutiny in both the U.S. and South Korea.

In an opinion piece published in 2023 in The Wall Street Journal, Ji Seong-ho, a member of South Korea’s Parliament who was born in North Korea and escaped in 2006, called Ahn a “phony” peace activist and alleged she was driven by a desire to see the U.S. and South Korea lose influence to North Korea and China more than any commitment to peace.

In particular, Ahn’s harsh criticism of the U.S. military and sanctions against North Korea, along with her direct engagement with North Korean officials, has led some to accuse her of being a pawn for the North Korean regime or even an outright agent — charges Ahn has vehemently denied.

However, even some vocal critics of the North Korean regime have defended Ahn. Tomas Ojea Quintana, who served as United Nations special rapporteur on human rights in North Korea until 2022, said of the ban in a statement that “this is a dangerous precedent that has to be clarified, because it affects the right to freely enter the country and freedom of expression.”

Ahn has notably formed a close working relationship with retired U.S. Air Force general Dan Leaf, who once served as deputy commander of U.S. forces in the Pacific at Camp Smith, in lobbying for pursuing a formal peace agreement with North Korea.

This is not Ahn’s first ban from South Korea. She was previously blacklisted by the administration of Korean President Park Geun-hye, but the ban was lifted when President Moon Jae-in succeeded Park in 2017.

Moon pursued a conciliatory approach to relations with the North, reopening dialogues in hopes of reducing hostilities. But in 2022 North Korea launched 95 ballistic and other missiles — more than any previous year — in a historic show of force, and moved to bolster military ties with Russia and China.

It was an election year. Anxious South Koreans voted out Moon and elected Yoon, who favors a much tougher approach to relations with the North and has sought to bolster his country’s military arsenal. During his campaign, Yoon even floated the prospect of South Korea developing nuclear weapons to match the North’s increasingly capable arsenal, though he has since backed off of the proposal.

Tensions between the two Koreas have continued to escalate, with ripples now reaching as far as Europe. North Korea is one of the only countries to openly support the Russian invasion of Ukraine and has sent weapons and more recently troops to support Russian forces. Now Yoon’s government is mulling directly providing weapons to Ukraine’s defending forces.

“Inter-Korean military tension has peaked, and pundits in Seoul and Washington are talking about the outbreak of a ‘Second Korean War.’” said Moon Chung-in, a diplomat-­turned-academic who served as a special adviser on national security to Moon Jae-in. “The absence of back-channel diplomacy and the mediating roles of big powers such as the U.S. and China, which used to serve as an effective mechanism for crisis aversion, is troubling us. Peace has vanished, and a dense fog of war has spread on the Korean peninsula.”

He said he was shocked when he first heard that the government had barred entry to Ahn, telling the Star-Advertiser, “Several observers speculate that she might have become a victim of the Yoon government’s anti-peace initiative. … President Yoon used to describe peace activists in South Korea and elsewhere as pro-North Korean.”

Moon Chung-in noted that Yoon’s government has championed itself as a defender of democracy, free speech and human rights in contrast to the authoritarian North Korean regime. He told the Star-Advertiser that “it is ironic to witness that the freedom-loving Yoon government banned Ms. Ahn, a renowned American citizen and a civic leader, from entering South Korea. … I expect major political repercussions at home and abroad from this undemocratic behavior.”

The apparent ban comes as the U.S. State Department is finishing its annual human rights report for South Korea. Ahn said she hopes that will give her some leverage to see the ban overturned. The U.S. and South Korea have sought to tighten their alliance in recent years amid tensions across the Pacific.

However, the election Tuesday of former President Donald Trump back to the White House presents a potential wild card for U.S. policy toward the Korean Peninsula.

When Trump was previously president, he questioned the value of alliances like that between the U.S. and South Korea, and was largely ambivalent about putting pressure on other countries over their human rights records. Trump’s position on North Korea is also uncertain.

In 2018, North Korean leader Kim Jong Un and Trump traded threats and insults, with Trump boasting he would unleash “fire and fury” on the Korean Peninsula. As the war of words escalated, a false-alarm missile alert went out to cellphones across Hawaii on Jan. 13, 2018, terrifying residents. But later that year Trump met face to face with Kim in a historic summit in Singapore, and Trump has said the two have continued to have friendly correspondence.

On Wednesday (Thursday in South Korea), Yoon and Trump spoke by phone. Yoon told reporters at a news conference afterward that “we agreed to meet in the near future. … I believe there will be an opportunity to meet within this year.”