NEW YORK (AFP) - The United States on Tuesday asked North Korea to look at Iran's example, saying it was willing to negotiate with a hostile nation when it is "serious" about its promises.

Amid high tensions between North Korea and its neighbors, Deputy Secretary of State William Burns said that the United States remained firmly opposed to North Korea's nuclear weapons program but was open to diplomacy.

"We have consistently said we are willing to engage when countries show a credible and serious interest in abiding by their obligations. This was true in Burma, it's the case with Iran, and it can be the case with North Korea as well," Burns said at the Asia Society in New York.

But echoing other US officials, Burns said that the United States will not "buy the same horse twice." "We are not going to talk for the sake of talks or respond to North Korean provocations with inducements and concessions," he said.

North Korea has called on the United States to resume six-nation talks that involve its ally China. But leader Kim Jong-Un has refused commitments from previous agreements to give up nuclear weapons in return for aid and security guarantees.

The United States and five other powers are negotiating with Iran and have reached a preliminary agreement under which the Islamic republic has frozen sensitive nuclear work in return for sanctions relief.

Iran, an arch-enemy of the United States since its 1979 revolution, denies charges by Israel and some Western officials that it is seeking nuclear weapons, unlike North Korea which has carried out three nuclear tests in response to what it describes as US hostility.

Myanmar, earlier known as Burma, opened talks with the United States in 2009 to end its longtime pariah status and has since taken sweeping democratic reforms. President Barack Obama has responded by ending most sanctions on Myanmar, despite concerns over treatment of minorities.

Obama took office in 2009 with an offer to speak to US adversaries if they "unclench" their fists. North Korea has mostly been an exception, with the Obama administration repeatedly frustrated by the regime's actions.

In recent weeks, North Korea has conducted live-fire drills near the disputed border with South Korea, test-fired ballistic missiles capable of hitting Japan, flown rudimentary drones into the South and threatened to carry out a "new" type of nuclear test.