Moscow, June 1 : The US is "adding fuel to fire" by supplying weapons to Kiev, Kremlin spokesman Dmitry Peskov said on Wednesday in response to US President Joe Biden's decision to provide more advanced missile systems to Ukraine, media reports said. "We believe that the United States is purposefully and diligently adding fuel to the fire," Peskov told reporters on a regular conference call, CNN reported. The Ukrainian authorities have long asked the United States to supply high-tech, medium-range rocket systems. Biden said on Tuesday the US is providing Ukraine "more advanced rocket systems and munitions" as its war with Russia grinds on. "Such supplies do not contribute to the Ukrainian leadership's willingness to resume peace negotiations," Peskov said, CNN reported. Peskov also added the Kremlin does not trust Ukraine President Volodymyr Zelensky's words that Kiev would not use multiple launch rocket systems to attack the Russian territory if they receive them from the US. Washington's arming of Ukraine with heavier weapons increases the risk of direct US-Russia confrontation regardless of American statements that they want to mitigate this risk, Russian Deputy Foreign Minister Sergey Ryabkov said on Wednesday. The diplomat was commenting on the news that the US has decided to supply HIMARS multiple rocket launchers to Ukraine. Any arms supplies, which continue and escalate, increase the risk of such a development," Ryabkov told journalists, referring to the possibility of a direct confrontation between Russia and the US, RT reported. /IANS