The influential sister of North Korean leader Kim Jong-un has warned the US not to "cause a stink", as President Joe Biden prepares to set out his Korean policy.

In remarks on state media, Kim Yo-jong criticised the US and South Korea for conducting joint military exercises.

Her comments come a day before top US officials are due to arrive in Seoul.

The US government has said it has been trying for weeks to make diplomatic contact with North Korea.

Pyongyang has yet to acknowledge that President Biden is now in office.

The two countries remain at loggerheads over the North's nuclear and ballistic missile programmes.

Kim Yo-jong was quoted in the official Rodong Sinmun newspaper as saying: "A word of advice to the new administration of the United States that is struggling to spread the smell of gunpowder on our land from across the ocean.

"If it wants to sleep in peace for [the] coming four years, it had better refrain from causing a stink at its first step."

She reiterated her country's opposition to the joint military exercises - which North Korea describes as preparations for invasion - saying: "The South Korean government yet again chose the 'March of War', the 'March of Crisis'."

Kim Yo-jong is the younger sister of Kim Jong-un and the only one of his siblings considered a close and powerful ally.