North Korea says it has been deceived by the U.S. and that the the past 18 months were nothing but lost time as Washington has attempted to work toward denuclearization.

In a statement published by state news agency KCNA on Saturday, Kim Kye Gwan, a top adviser to Kim Jong UnKim Jong UnSouth Korea says it shared Trump birthday message with Kim Jong UnThe Hill’s Morning Report Impeachment tug-of-war expected to end soonNorth Korean nuclear threat is hereMORE, said the North Korean leader had received “birthday greetings from the U.S. president” this week, but their personal relationship is not enough to restart talks.

“Although Chairman Kim Jong Un has a good personal feelings about President TrumpDonald John TrumpIran says it ‘unintentionally’ shot down Ukrainian planePuerto Rico hit with another major earthquake as aftershocks continueTrump empathizes with Queen Elizabeth II after Harry and Meghan’s royal exitMORE, they are, in the true sense of the word, ‘personal’,” the Pyongyang foreign ministry official said.

We have been deceived by the United States, being caught in the dialogue with it for over one year and a half, and that was the lost time for us.

Nuclear negotiations between the two sides broke down last year after little substantial progress, and Saturdays statement indicates North Korea may be difficult to bring back to the table.

“There will never be such negotiations as that in Vietnam, in which we proposed exchanging a core nuclear facility of the country for the lift of some U.N. sanctions in a bid to lessen the sufferings of the peaceable people even a bit, it said.

Tensions rose between the U.S. and North Korea late last month after Pyongyang warned that the U.S. would receive a Christmas gift and later that it would soon witness “a new strategic weapon.

Trump had made improving relations with Kim a centerpiece of his Asian foreign policy, but following a pair of summits and the presidents historic visit to the demilitarized zone between North and South Korea diplomatic efforts have chilled substantially.

“What is clear is that we will never lose our time again, being taken in by the U.S. trick as in the past,” North Korea said Saturday.