The US is seeing signs that Russia may offer to help Iranian authorities <a href="https://www.thenationalnews.com/mena/iran/2022/10/23/mahsa-amini-protests-activists-say-irans-crackdown-is-intensifying/" target="_blank">crack down on demonstrators </a>in what has become the biggest popular protest movement in the country since 2009, a senior official said on Wednesday. The development comes amid deepening ties between Moscow and Tehran, which the US says is<a href="https://www.thenationalnews.com/world/us-news/2022/10/20/iranian-troops-working-with-russians-in-crimea-to-strike-ukraine-with-drones-us-says/" target="_blank"> providing killer drones for Russia</a> to use in <a href="https://www.thenationalnews.com/tags/ukraine" target="_blank">Ukraine.</a> Protests erupted across Iran last month following the death of 22-year-old Mahsa Amini in police custody. The regime has resorted to violence, intimidation and mass arrests but has not been able to silence dissent. On Wednesday, <a href="https://www.thenationalnews.com/mena/iran/2022/10/26/mourners-defy-iranian-police-to-gather-at-mahsa-aminis-grave-40-days-after-she-died/" target="_blank">thousands of mourners</a> marched to Amini’s gravesite in Saqez while chanting slogans against the regime. “We see signs that they [the Russians] may be considering the ability to help train Iranians on cracking down on protesters,” White House national security spokesman John Kirby told reporters. He added that Washington is “concerned that Moscow may be advising Iran” already. Mr Kirby did not say how Russia would help Iran, but Moscow has frequently used repressive measures against its own protesters. The Kremlin has also made journalists and opposition leaders into targets in the past. Iran's crackdown has left at least 141 people dead and<a href="https://www.thenationalnews.com/mena/iran/2022/10/24/mahsa-amini-killing-new-protests-and-clashes-erupt-in-tehran/"> hundreds detained</a> and arrested, activists say, and its actions have been condemned by <a href="https://www.thenationalnews.com/world/2022/10/25/uk-condemns-irans-barbaric-use-of-live-ammunition-and-bird-shot-against-protesters/">nations around the world.</a> It is the biggest show of popular unrest in Iran since 2009, when hundreds of thousands took to the streets to protest against what they said was the rigged election of Mahmoud Ahmadinejad. Moscow-Tehran co-operation has increased following Russia's purchase of <a href="https://www.thenationalnews.com/world/us-news/2022/10/25/israels-president-herzog-presents-us-with-evidence-of-iranian-weapons-in-ukraine/" target="_blank">Iranian-made drones</a> that it has used in Ukraine. On Monday, Ukrainian President Volodymyr Zelenskyy said Russia has ordered 2,000 more kamikaze drones from Iran. Mr Kirby's comments came as US President Joe Biden met his defence chiefs at the White House. Mr Kirby said Mr Biden recommitted to lead on helping Ukraine and discussed other pressing issues such as combating climate change. He also said his administration is not seeking conflict, but “stiff competition” with China.