(Scott Eells/Bloomberg)

South Korean President Lee Myung-bak on Thursday praised Congress’s ratification of a U.S.-Korea pact representing the largest free trade agreement since the North American Free Trade Agreement, calling the deal a “historic achievement,” a “win-win for both countries” and “a major step toward future growth and job creation.”

“Thanks to all of you in this chamber, our economic ties are becoming even stronger,” Lee said in an address before a joint meeting of Congress one day after the House and Senate overwhelmingly approved the trade deal, which the Obama administration has said will boost U.S. exports by as much as $11 billion and will lead to the creation of hundreds of thousands of jobs.

Noting that his address to Congress comes 58 years after the United States and South Korea signed their mutual defense pact in October 1953, Lee told the lawmakers and others assembled in the House chamber Thursday afternoon that the trade pact represents a new landmark in U.S.-Korea relations.

“Here, where the Mutual Defense Treaty was signed by Korea and the United States in 1953, a new chapter in our relationship has opened,” Lee said. “Our relationship has become stronger.”

The speech, which marked the first address by a South Korean leader to Congress since Kim Dae-jung spoke in June 1998, came hours after Lee met with President Obama Thursday morning. The White House will fete Lee with a state dinner Thursday night, and both presidents are expected to travel together Friday to tour a General Motors factory in Detroit.

House and Senate leaders as well as several dozen rank-and-file members were present in the chamber Thursday afternoon for Lee’s speech, which the South Korean president delivered in Korean. Those in attendance listened to a simultaneous English interpretation of the address through headphones and several times greeted Lee with applause and standing ovations.

One of the main issues facing the United States and South Korea is the North Korean nuclear program. Since 2008, multilateral talks among all three countries as well as China, Japan and Russia have been at a standstill, and the issue looms large over U.S. foreign policy in the region.

In his address Thursday, Lee called on North Korea to abandon its nuclear program and emphasized that the United Stares and South Korea remain united in their approach toward the North.

“I recognize the reality that Korea has been split in two, but I will never accept it as a permanent condition. ... We therefore must achieve the denuclearization of the Korean Peninsula, and North Korea must give up their nuclear ambitions,” he said. “Korea and the United States stand united. We are in full agreement that the six-party talks is an effective way to achieve tangible process. We are in full agreement that we must also pursue dialogue with North Korea. However, we must also maintain our principled approach.”

Lee stressed the importance of the U.S.-Korean alliance and was greeted by an extended standing ovation when he thanked by name the lawmakers who served in the Korean War — Reps. Charlie Rangel (D-N.Y.), John Conyers (D-Mich.), Sam Johnson (R-Texas) and Howard Coble (R-N.C).

“To these gentlemen and to millions of others, the Korean War or the division of the Korean Peninsula are not abstract concepts,” Lee said, describing the U.S.-Korea alliance as one “forged in blood.”

He also described U.S. leadership in Asia as of paramount importance.

“Your leadership that has ensured peace and stability of Northeast Asia and beyond in the 20th century must remain supreme in the 21st century,” he said.

As is often the case during joint meetings, not all lawmakers were present. But one complicating factor on Thursday was that Lee’s speech was the first by a foreign leader since the elimination of the House Page Program. For decades, the pages — high-school juniors who serve as errand-runners for members of Congress — typically had been called upon to fill the seats of the chamber in case too few lawmakers are present.

On Thursday, there were few empty seats in the chamber. Most were occupied not by pages or lawmakers, but by Capitol staffers and members of the Korean delegation.