North Korea on Saturday rejected the idea of resuming talks to end its nuclear program, saying previous such attempts ended in failure, and reiterated its demand that the US come to the table to negotiate a peace treaty.

The statement by the North’s foreign ministry came a day after President Obama and South Korean president Park Geun-hye said in Washington they were open to talks with North Korea on sanctions but that Pyongyang needed to show it was serious about abandoning its nuclear ambition.

“If the United States insists on taking a different path, the Korean peninsula will only see our unlimited nuclear deterrent being strengthened further,” the North’s foreign ministry said in a statement.

North and South Korea remain technically at war under a truce it signed in 1953 with the US, which led United Nations forces backing the South, and China, which fought for the North.

North Korea walked away from the so-called six-party talks involving the US and four other countries in 2008 and went on to conduct two more nuclear tests.

It said only a peace treaty with Washington could permanently resolve the conflict on the Korean peninsula.

On Friday, Obama said the US was open to negotiations that could ease sanctions imposed on the North, just as it had done with Iran, which reached a deal in July with major powers.

“We haven’t even gotten to that point yet, because there has been no indication on the part of the North Koreans as there was with the Iranians that they could foresee a future in which they did not possess or were not pursuing nuclear weapons,” he said.