SAN FRANCISCO (Yonhap) -- President Lee Myung-bak said Tuesday Korea will no longer put up with North Korean provocations, vowing to strike back harder at the communist regime if it attacks the South.

"We, the Republic of Korea, have always put up with (North Korean provocations), not because we lacked strength, but in order to maintain peace," Lee said during a meeting with South Koreans in San Francisco.

"But we've learned that tolerance is not the way to deter provocations. Now it is our firm policy that if (the North) makes provocations, it will get greater punishment," he said, drawing applause from the audience.

Lee also said South Koreans should be more united to maintain peace on the peninsula.

Lee arrived in San Francisco on Tuesday for a stopover after a Latin American trip that included stops in Mexico, Brazil, Chile and Colombia.

Lee reiterated his call for Pyongyang to give up its nuclear programs and open up to the outside world, saying the international community, especially South Korea, will rush to help the impoverished nation if it does so.

Lee also said the South has no intention of toppling and absorbing the North.

"We want to get North Korea to open up and give up its nuclear programs so that it will be well off and then seek peaceful unification. This is our goal," he said.

Earlier in the day, Lee met with San Francisco Mayor Edwin Lee.

President Lee said San Francisco is playing an important role as a U.S. West Coast gateway for exchanges with South Korea, and asked the mayor for greater attention and support for the Korean community in the city, the office said.

The president also praised the progress the American city has made in government finances, employment and policing since the first Asian-American mayor of San Francisco took office in January 2011.

The mayor briefed the South Korean leader on his "Green Capital" policy aimed at making the city more environment-friendly, and expressed his interest in cooperation with Korea on green growth, the office said.