The United States has accused North Korea of supplying Russia with a “significant” number of artillery shells to be used in Ukraine, as Moscow increasingly seeks help from allies in the war effort. US National Security Council spokesman John Kirby told reporters on Wednesday that North Korea’s alleged arms shipments are unlikely to change the course of the conflict, underscoring Western efforts to support the Ukrainian military. “Our indications are that the DPRK is secretly supplying and we will be watching to see if the shipments are being received,” Kirby told reporters, referring to North Korea by its acronym, the Democratic People’s Republic of Korea. He did not share details about how it would be transported or whether the U.S. would attempt to ban shipments to Russia. Tuesday’s announcement comes amid heightened U.S. tensions with North Korea, which fired nearly two dozen missiles on Wednesday, including one that landed near South Korean waters. Pyongyang has conducted a record number of weapons tests this year in defiance of US and international sanctions. Earlier in the week, US and South Korean forces held large, joint air exercises, prompting an angry response from North Korea, which described the drills as a “relentless and reckless” provocation. On Tuesday, US State Department spokesman Ned Price said Pyongyang appeared to be “looking for another pretext for provocations that it has already undertaken, possibly provocations that it may be planning to make in the coming days or weeks.” The US has warned competitors and adversaries – including China – not to come to Russia’s aid in Ukraine. Washington and Kyiv have also accused Tehran of supplying Moscow with drones used in deadly attacks across Ukraine – claims Iran has denied. Last month, Kirby said Iranian personnel were “directly involved on the ground” in Crimea to help train Russian forces in the use of drones. The US and the European Union have imposed sanctions on Iranian individuals and companies they accuse of links to the country’s drone industry and missions to Russia. Since Russia launched its all-out invasion of Ukraine in February, its military campaign has been mired in setbacks. In recent months, Ukrainian forces, backed by US weapons, have recaptured large swathes of territory in a counter-offensive in the east of the country. Washington and its allies have imposed sanctions on Russia over the war and are providing military and humanitarian aid to Ukraine. In September, the US Congress approved a bill to make $12 billion in funds available for Ukraine, adding to the tens of billions of dollars in aid approved earlier this year.