President Barack Obama and South Korean President Lee Myung-Bak radiated warmth and praised a finally unblocked trade deal as a win for both nations during a friendly state visit. Standing side-by-side the leaders also spoke with "one voice" on North Korea, warning the Stalinist state faced even deeper isolation if it continued provocations and its nuclear program. Obama feted Lee at the White House with military honors and a glittering black tie state dinner, and praised his guest's energy and enthusiasm, which he said fully justified his nickname of the "bulldozer." Earlier, both men hailed a long-delayed bilateral free trade pact, which was endorsed by the US Congress on the eve of their talks, after years held up by political wrangles in Washington and market access wrangles. "It's a win for both our countries," Obama said, arguing the deal would boost American exports by up to $11 billion and support 70,000 US jobs. Under severe political pressure as the US recovery stutters and with unemployment at 9.1 percent, Obama said the deal would help US automakers and open Korean agricultural, aerospace and electronics markets. Using the same script, Lee also described the deal as "a win for both of our countries" billing the deal as a "historic achievement" that would further cement the 60-year alliance between Seoul and Washington. He said he was confident the pact would also be ratified by South Korea's parliament in the "near future." The leaders did not break new ground on North Korea, but their firm friendship, and the similarity of their language, reflected an apparently watertight US-South Korean stance towards Pyongyang. "Together we've succeeded in changing the equation with the North, by showing that its provocations will be met not with rewards but with even stronger sanctions and isolation," Obama said. "If Pyongyang continues to ignore its international obligations, it will invite even more pressure and isolation," he said, but promised more opportunity if North Korea abandoned its quest for nuclear weapons. Lee said after private Oval Office talks with Obama and an expanded meeting with delegations, that on North Korea, the two governments "speak with one voice and we will continue to speak with one voice." Tensions flared last year when Seoul accused the North of torpedoing one of its warships, killing 46 people, and last November the North bombarded a frontier island further enflaming ties with the south. But last month, the two Koreas held a second round of talks designed to pave the way for a resumption of six-nation talks on the North's nuclear program and US and North Korean officials met in New York in late July. Another meeting is expected soon, though it is not clear if either side believes tangible process is possible, or fear they need to mitigate a possible new round of provocations from Kim Jong-Il's hermit regime. Lee also touched on North Korea in an address to a joint session of Congress, saying the six party talks also including Russia, the North, Japan and China were the best way to forge "tangible" progress. "We are in full agreement that we must also pursue dialogue with North Korea. However, we must also maintain our principled approach," Lee said, according to a copy of his prepared remarks. Before the state dinner, Obama and his wife Michelle greeted Lee and his wife Kim Yoon-Ok, wearing a traditional Korean Hanbok gown, under the North Portico of the White House. Guests included UN Secretary General Ban Ki-moon, Facebook Chief Operating Officer Sheryl Sandberg, tennis great Billie Jean King, and LPGA golfer Christina Kim, as well as top officials and business leaders. Obama toasted the US-South Korea alliance as "a partnership of the heart that will never be broken"while Lee said his nation would never forget US sacrifices in the Korean war. Lee's visit was meant to honor one of Obama's closest friendships on the world stage and one of America's most functional foreign relationships, and further anchor his policy of making Asia the key to future US prosperity. Lee and Obama will travel together on Friday to a Michigan General Motors plant to highlight the trade pact, which ironically was once hung up on the issue of auto imports.