WARSAW, Poland -- President Yoon Suk Yeol is set to depart for Seoul on Sunday, concluding a weeklong visit to Lithuania, Poland and Ukraine, with an emphasis on global security, business reinforcement with NATO members and Ukrainian reconstruction.

Yoon made an unexpected stop in Ukraine on Saturday, where he promised military supplies and financial aid. Yoon’s journey involved a mix of air, land and train travel, totaling 27 hours for the round trip. He stayed in Ukraine for 11 hours.

The Korean government has arranged nine packages for cooperation, covering security, reconstruction and humanitarian assistance, according to Deputy Director Kim Tae-hyo of the National Security Office on Sunday.

He said these packages encompass an increase in military supplies, an expansion of international cooperation for food and energy security, and more support for safety equipment such as mine detectors and mine removers.

"We're planning and organizing defense industry cooperation between Korea and Ukraine over the mid-to long-term, and we've received Ukraine's request for Korean involvement in future reconstruction projects,” Kim said.

When asked about possible supplies of lethal weapons, Kim said Yoon was invited on the understanding that South Korea does not directly supply destructive weapons to Ukraine. However, “Ukraine showed interest in mine detection and removal equipment, diverse humanitarian aid for children, digital equipment and educational programs for students."

The presidential office had denied in May reports that Yoon would visit Ukraine during his trip to Europe this month, but his pledge of additional support was not entirely a surprise.

Throughout his stay in Poland and Lithuania, he consistently expressed Korea’s willingness to participate in Ukraine's reconstruction. In a joint statement with Poland, he denounced Russia's invasion of Ukraine, declaring South Korea as an “optimal partner” for Ukraine's reconstruction.

Korea signed a memorandum of understanding with Poland on cooperation in rebuilding Ukraine. Deputy Director Kim Tae-hyo of the National Security Office said the agreement has paved the way for economic relationships with Ukraine. He estimated that Ukraine's reconstruction would involve projects worth over 2,000 trillion won ($1.5 trillion).

Yoon’s economic secretary Choi Sang-mok said, “The Ukrainian government is looking beyond rebuilding from war damage and instead focusing on new construction to enhance the national system.” Consequently, starting in the second half of this year, South Korea decided to assist in establishing a smart city master plan in Kyiv and Uman.

In Poland, Yoon met entrepreneurs interested in participating in the Ukraine reconstruction project. The companies are in sectors including construction, energy, water resources, information technology, railroad vehicles and construction machinery.

While Yoon was in Poland, Hyundai Engineering & Construction signed a memorandum of understanding with Ukraine's Boryspil International Airport for reconstruction of the airport. Samsung C&T signed an MOU with the city of Lviv, located in the westernmost part of Ukraine, and Onur, a Turkish construction company, for cooperation in the development of smart cities in Lviv.

South Korea is not alone in its interest in the Ukraine reconstruction project. Over 500 businesses from 42 countries and 21 economic sectors with a total market cap exceeding $5.2 trillion recently signed the Ukraine Business Compact, a pledge of international business support for Ukraine’s recovery.

The World Bank estimates Ukraine's reconstruction will cost over $400 billion, three times the country's gross domestic product. Since Russia's invasion in February 2022, external contributors have infused $59 billion into Ukraine.

But the official said Korea's move should start with humanitarian aid before talking about business.

"For instance, an urgent need, especially in Ukraine, is to dispose of the wreckage," he said. "There are Korean companies that have these skills, and this work mixes humanitarian aid and business issues."

During Yoon’s surprise visit to Ukraine on Saturday, Yoon pledged $150 million in humanitarian aid, following last year's contribution of around $100 million.

The two leaders agreed to jointly pursue the “Ukraine Peace and Solidarity Initiative,” which includes South Korean security aid, humanitarian aid and reconstruction aid.

When Yoon attended the NATO summit in Lithuania, he raised the issue of a post-war restoration project in Ukraine. During his speech at the NATO summit, Yoon announced the Korean government's participation in NATO's “Ukraine Trust Fund.”

During his bilateral meetings with 13 leaders of NATO allies and partners held on the sidelines of the summit, Yoon consistently brought up the Ukraine issue, reaffirming South Korea’s commitment to universal values such as freedom, human rights and the rule of law.

In addition to Ukraine rebuilding, Yoon also promoted economic and security cooperation with NATO members and partners during his week-long trip to Europe.

In Poland, South Korean and Polish businesses formalized 33 memorandums of understanding across the tech, energy and service industries. The 33 deals include 11 within tech sectors, such as battery tech and future vehicles. Another 13 involve the energy sector, including nuclear power, hydrogen and eco-friendly energy, while the remaining nine concern services industries, such as finance and tourism.

At the NATO summit in Vilnius, Yoon condemned North Korea's latest intercontinental ballistic missile launch, urging a stronger collective response from NATO. Yoon expressed his hope for continued close collaboration between South Korea and NATO in the future, aiming for the denuclearization of North Korea.