Seoul, Jan 29 : A senior North Korean official on Sunday rejected alleged weapons transactions with Russia, warning the US of an "undesirable result" if it continues to spread such rumours. Kwon Jong-gun, director-general in charge of US affairs at North Korea's foreign ministry, claimed the US again talked about the "groundless rumour" of arms dealing between North Korea and Russia in an attempt to justify its offer of weapons to Ukraine, Xinhua News Agency reported. The US has recently announced its decision to send 31 M1 Abrams tanks to Ukraine to help its fight against Russia's invasion. Kim Yo-jong, the powerful sister of the country's leader Kim Jong-un, said Washington is crossing the "red line." "Trying to tarnish the image of the DPRK by fabricating a non-existent thing is a grave provocation that can never be allowed and that can not but trigger its reaction," Kwon said in a statement carried by North Korea's official Korean Central News Agency, referring to North Korea by its official name, the Democratic People's Republic of Korea. "The US should be mindful that it will face a really undesirable result if it persists in spreading the self-made rumour against the DPRK." Kwon did not say what he meant by an undesirable result. Earlier this month, the US said North Korea continues to provide ammunition to Russia, releasing satellite imagery of Russian railcars travelling between Russia and North Korea on November 18 and November 19 for what the US called the initial delivery of North Korean weapons to a private Russian military company, the Wagner Group, for use in Ukraine. /IANS