Yoon tells Congress the US-South Korea alliance is 'stronger than ever'

South Korean President Yoon Suk Yeol touted his country's longstanding partnership with the United States in an address before a joint meeting of Congress on Thursday.

Yoon, who received a standing ovation from all members and guests as he entered the chamber, was introduced by House Speaker Kevin McCarthy before delivering a speech celebrating the alliance's 70th anniversary.

"We know that no matter where you sit, you stand with Korea," Yoon said, telling lawmakers the U.S.-South Korea relationship is "stronger than ever."

Yoon, a conservative elected in 2022, has repeatedly emphasized global freedom since taking office. That theme was front and center in his speech to Congress, during which he lauded the U.S.-South Korea alliance as a "linchpin" in safeguarding freedom.

He paid tribute to American soldiers who fought in the Korean War and highlighted the U.S. and South Korea fighting side by side in Afghanistan, Iraq and other international conflicts.

"Those who cherish freedom also respect the freedom of others," Yoon said. "Thus, freedom brings peace. Peace, in turn, safeguards freedom. Freedom and peace are sources of creativity and innovation. They bring prosperity and abundance."

Yoon also spoke to lawmakers about the threats to democracy, including those posed by North Korea.

"North Korea's nuclear program and missile provocations pose a serious threat to the peace on the Korean Peninsula and beyond," he warned.

On Wednesday, President Joe Biden and Yoon held a bilateral meeting to discuss efforts to deter North Korea's nuclear threats, promote peace in the Taiwan straits, stand with Ukraine amid Russia's invasion and more. They announced new measures -- dubbed the "Washington Declaration" -- designed to prevent North Korea from launching a nuclear attack on South Korea. Those commitments include the U.S. docking nuclear-armed submarines in South Korea for the first time in decades and the strengthening of joint military training and simulation.

Appearing side-by-side at a joint press conference, both leaders hailed the importance and strength of the alliance.

"Our relationship has been a great success story," Biden said. "An alliance formed in war, and it's flourished in peace. Seemingly every day we've launched new areas of cooperation, all areas that matter most to our future."

The alliance, forged in the aftermath of the Korean War, will be critical for South Korea as it stares down North Korean aggression and Chinese expansion in the Indo-Pacific region.

"This is really a very impressive moment for the relationship," said Scott Snyder, a senior fellow for Korea studies at the Council on Foreign Relations. "The U.S. and South Korea have evolved to be working on so many different issue areas, and the scope of the relationship has broadened out beyond the peninsula to become more regional and global."

But the trip isn't without diplomatic and economic tension.

A recent leak of classified U.S. intelligence documents seemingly showed Washington was spying on South Korea's leadership. Yoon played down the spying suggestion during Wednesday's press conference, stating the two nations are in communication and are "sharing necessary information" as the U.S. investigation into documents' disclosure plays out.

Some South Korean officials have expressed concern about two major pieces of American legislation -- the Inflation Reduction Act and the Chips and Science Act -- stating provisions of the laws discriminate against Korean businesses.

Biden, pressed on whether the Chips Act was damaging to the key ally, defended the law as a "win-win."

"Two significant South Korean companies decided they were going to invest billions of dollars in chip manufacturing in the United States," he said. "It wasn't designed to hurt China, it was designed to, so we didn't have to worry about whether or not we had access to semiconductors."

Yoon said the U.S. and South Korea have agreed to coordinate so that the laws "can further strengthen supply chain cooperations between the two countries in advanced technology."

Meanwhile, Yoon has faced pressure from the U.S. and NATO to provide artillery to Ukraine as it faces depleted stocks. The leaked U.S. documents included descriptions of South Korea's National Security Council's internal discussions about the U.S. request to provide artillery ammunition to Ukraine.

South Korea's longstanding policy has been not to provide lethal weapons to countries at war.

Yoon said Thursday that South Korea "strongly condemns the unprovoked attack against Ukraine" and will work to safeguard its freedom and support the nation's reconstruction. He made no mention of artillery.

A hot-mic moment last year also caught Yoon insulting U.S. members of Congress as "idiots" if they didn't approve funding to the Global Fund, an organization dedicated to fighting AIDS, tuberculosis and malaria.

-ABC News' Lauren Peller, Chris Boccia and Ben Gittleson contributed to this report.