His patience tested, President Barack Obama on Saturday promised a new and stronger response to defiant North Korea, saying that while he prefers diplomacy he is now taking a "very hard look" at tougher measures. A Pentagon official said no military moves were planned. Obama's blunt language seemed to point toward nonmilitary penalties such as financial sanctions against North Korea, either within the United Nations or by Washington alone. US allies in Asia may consider new moves to improve their own military defenses. "We are not intending to continue a policy of rewarding provocation," he said, alluding to recent North Korea nuclear and missile tests. North Korea presents a challenge for Obama, already burdened with wars in Iraq and Afghanistan and concern about Iran's nuclear ambitions. The North poses a military threat to South Korea, with large artillery forces capable of striking Seoul with little or no warning, and previous diplomatic approaches to the North have failed to rid it of nuclear weapons or halt its building of missiles. "We are going to take a very hard look at how we move forward on these issues, and I don't think that there should be an assumption that we will simply continue down a path in which North Korea is constantly destabilizing the region and we just react in the same ways by, after they've done these things for a while, then we reward them," Obama said. Administration officials have talked in recent days of possible further penalties against North Korea, already one of the most isolated nations. Defense Secretary Robert Gates has advised Asian allies that additional military defensive measures might be warranted in light of North Korea's pattern of defiance in advancing its missile and nuclear arms programs. On a different front, Obama won support from French President Nicolas Sarkozy on seeking a Mideast peace that provides for Israeli and Palestinian states, and on the need to thwart Iran's disputed nuclear ambitions. The State Department said Friday the US is considering imposing its own financial penalties against North Korea, in addition to whatever punishment the UN takes in response to the North's recent nuclear test. Secretary of State Hillary Rodham Clinton met with South Korea's foreign minister, Yu Myung-Hwan, in Washington on Friday amid indications the reclusive communist government was preparing to test a missile that could reach U.S. territory. The North recently conducted a barrage of missile launches and an underground nuclear test that violated previous UN Security Council penalties. Clinton told reporters that U.N. diplomats were making progress on new penalties. In his remarks Saturday, Obama was more blunt about the limits of US patience. "North Korea's actions over the last several months have been extraordinarily provocative and they have made no bones about the fact that they are testing nuclear weapons, testing missiles that potentially would have intercontinental capacity," the president said. Earlier Saturday, South Korean President Lee Myung-bak delivered a stern warning to the North in a nationally televised speech honoring the country's war dead. "I would like to make it clear that there will be no compromise against things that threaten our people and security," Lee said. At an earlier point in the long-running struggle to put a lid on North Korea's nuclear ambitions, President Bill Clinton's administration in the mid-1990s discussed with urgency the possibility of taking military action. That seems less likely now, since the North evidently is nuclear-armed and other nations are focused first on searching for a nonmilitary solution. While traveling in Asia last weekend, Gates said North Korea's behavior was "reckless" and that while Obama was open to dialogue with adversaries, he is "not naive." "We will not stand idly by as North Korea builds the capability to wreak destruction on any target in the region or on us," Gates said. In meetings with South Korean and Japanese officials, he said it was time to think about additional defensive moves they could make, collectively or individually, to prepare for the possibility of North Korea continuing to develop its nuclear capability. Gates mentioned no specific possibilities. One possible option could be to put more Navy ships in waters near the Korean Peninsula to provide more capability to shoot down hostile missiles. Pentagon press secretary Geoff Morrell said Saturday that the US is not moving toward military action against North Korea. "That's not the focus of our efforts," Morrell said. "Everyone's preference is to prevail upon the North Koreans with diplomatic or economic pressure. But Secretary Gates on his most recent trip to Asia urged our allies - Japan and South Korea - to begin thinking about prudent defensive measures that might also be taken should we fail in dissuading the North Koreans from pursuing" ballistic missile and nuclear bomb capabilities. Morrell said the US is not planning to send additional troops to South Korea, where there already are about 28,500 on station. Obama mentioned that Russia and China, two of the six nations in the disarmament talks, responded more forcefully to North Korea's recent tests than they had in the past. He said this was an indication that Moscow and Beijing share the US view that North Korea's repeated defiance of international demands is destabilizing the region. "My preference is always to use a diplomatic approach," Obama said. "But diplomacy has to involve the other side engaging in a serious way in trying to solve problems. And we have not seen that kind of reaction from North Korea. So we will continue to consult with our allies." The US, Russia, China, Japan and South Korea are seeking to get North Korea back to the bargaining table, with little progress so far. Obama did not mention it, but the Bush administration agreed to remove North Korea from the US list of terrorist states after the North said it would dismantle its nuclear weapons facilities. It later refused to go forward with the dismantlement. Obama spoke after a private meeting with Sarkozy, who told reporters that on the matter of North Korea, "we have total convergence of views with the American president." Later the two presidents flew to the Normandy coast to mark the 65th anniversary of the D-Day invasion that turned the tide of World War II in Europe. On Iran, Sarkozy said "we do not want military nuclear weapons to spread and we are clear on that." On Wednesday he had met with Iran's foreign minister, Manouchehr Mottaki, and told him "to take this hand stretched out by Barack Obama." Obama reaffirmed that there must be "tough diplomacy" with Teheran and said Iran's actions are contrary to its leaders' insistence that the country does not seek nuclear weapons.