The sister of North Korean leader Kim Jong Un has lashed out at South Korea's government, days after it said it was considering new sanctions over the regime's recent missile tests.
Kim Yo Jong called South Korea's conservative president Yoon Suk Yeol and his administration "idiots who continue creating the dangerous situation", two days after Seoul's foreign ministry said it was mulling additional measures against Pyongyang.
The barrage of tests include the launch of an intercontinental missile earlier this month, which "could have covered the entire US mainland".
Seoul is also considering taking action against alleged cyber attacks by North Korea, believed to be an important new source of funding for its weapons programme, if the secretive state carries out a major provocation like a nuclear test.
In a statement reported by state media, Ms Kim said: "I wonder what 'sanctions' the South Korean group, no more than a running wild dog gnawing on a bone given by the US, impudently will impose on North Korea.
"What a spectacle!"
She continued to issue a warning to the "impudent and stupid", saying: "Desperate sanctions and pressure of the US and its South Korean stooges against (North Korea) will add fuel to the latter's hostility and anger and they will serve as a noose for them."
Responding to Ms Kim's insults, Seoul said it was "very deplorable for her to denounce our head of state with rough, substandard words and show no basic forms of etiquette".
The unification ministry, an executive department of the South Korean government, added it strongly condemns what it called Ms Kim's "impure attempt to incite anti-government struggles and shake our system".
Analyst Cheong Seong-Chang, from the private Sejong Institute in South Korea, said that although this is not the first time Ms Kim has used insults towards South Korea, the move is expected to further escalate military tensions on the Korean Peninsula.
Ms Kim's official title is vice department director of the Central Committee of the North's ruling Workers' Party, but South Korea's spy agency has said that she handles relations with both South Korea and the US.
It has also said she is the North's second-most powerful person after her brother.
Last month, South Korea announced new unilateral sanctions against 15 North Korean individuals and 16 organisations, the first in five years. The targets of these sanctions were suspected of involvement in illicit activities to finance North Korea's nuclear weapons and missile programmes.
Since 2006, North Korea has been under 11 rounds of United Nations sanctions, imposed over its nuclear and missile tests.
Both China and Russia backed tighter sanctions after Pyongyang's last nuclear test in 2017, but in May vetoed a US-led push for more UN penalties over its renewed missile launches.