Kim Yo-jong, the influential sister of North Korean leader Kim Jong-un, on Sunday reaffirmed the secretive country's nuclear status as “irreversible” and an “undeniable reality,” a day before Chinese President Xi Jinping's first visit in seven years.

“The strategy of relentlessly strengthening the defensive nuclear deterrent proclaimed by the head of state is irreversible” and North Korea's nuclear status is “absolute” and an “undeniable reality,” Kim Yo-jong said in a statement, published by the state news agency KCNA.

The North Korean president's sister described as "false information" the White House announcement that US President Donald Trump and Xi confirmed their "shared goal" of denuclearizing Pyongyang during the Republican's trip to Beijing last month.

The statements come a day before Xi travels to North Korea, his historic ally, a trip seen as an attempt by Beijing to preserve its influence amid North Korea's rapprochement with Russia.

China has traditionally opposed the North Korean nuclear program and has supported UN Security Council resolutions against Pyongyang, but in recent years it has reduced the public weight of that disagreement in favor of regional stability and political coordination with Kim.

This same week, Kim visited a newly opened nuclear plant, where he stated that the production capacity for weapons-grade nuclear material “has more than doubled” in the last five years, and cited “strengthening” nuclear forces “at an exponential rate” as a priority.