Russian President Vladimir Putin on Monday threatened to 'throttle' U.S. tech firms, including Microsoft and Zoom, on the heels of President Donald Trump's furious tirade against the Russian leader. 'They're trying to choke us, we should respond in kind,' Putin said, after being told that the two U.S.-based tech firms were still technically operating in Russia, despite officially pulling out due to the Ukraine war. Putin's comments came after the Kremlin said that Trump was showing signs of an 'emotional overload' after the president ranted to reporters Sunday that he didn't know 'what the hell happened to Putin.' In a Truth Social post later Sunday night, Trump also charged that Putin had gone 'gone absolutely CRAZY!' 'I've always said that he wants ALL of Ukraine, not just a piece of it, and maybe that’s proving to be right, but if he does, it will lead to the downfall of Russia!' Trump said. Russia has bombarded Ukraine with missiles and drone strikes in the past three nights, showing no signs of letting up despite Trump's demands for the war to end. A week ago, Trump and Putin were on the phone for two hours, with the U.S. president saying that the 'tone and spirit of the conversation were excellent.' 'If it wasn't, I would say so now, rather than later,' Trump said. But with no 30-day ceasefire agreement firmed up, as was proposed, Russia has continued to assault Ukraine, including the country's civilian population. Ukrainian officials estimated around 900 drones were launched by Russia in attacks from Friday through Sunday nights, the Associated Press reported. French President Emmanuel Macron reacted Monday by saying that the Russian attacks 'show the extent to which President Putin has lied to the Europeans and to the Americans.' On Monday, Republican Sen. Chuck Grassley, the Senate's president pro tempore, encouraged Trump to levy additional sanctions on Russia for the country's bad behavior. 'I’ve had enuf of Putin killing innocent ppl. Pres Trump Take action AT LEAST SANCTIONS,' the 91-year-old Iowa Republican posted on X. Trump told reporters Sunday at the Morristown Airport as he left his Bedminster golf club that he was considering such a move. The president said he was 'absolutely' open to more sanctions. 'I'm not happy with what Putin's doing. He's killing a lot of people,' Trump also said. 'I don't know what the hell happened to Putin. I've known him a long time. Always gotten along with him. But he's sending rockets into cities and killing people.' 'We're in the middle of talking and he's shooting rockets into Kyiv and other cities. I don't like it at all... I don't know what's wrong with him,' the president complained. Trump had stayed largely quiet throughout the weekend - as he delivered a commencement address at West Point and golfed at Bedminster - with Ukrainian President Volodymyr Zelensky encouraging him to react. 'The silence of America, the silence of others in the world only encourages Putin,' Zelensky wote on Telegram. 'Every such terrorist Russian strike is reason enough for new sanctions against Russia.' In turn, Trump wrote on Truth Social that Zelensky mouthing off wasn't helping matters. 'Likewise, President Zelensky is doing his Country no favors by talking the way he does. Everything out of his mouth causes problems, I don’t like it, and it better stop,' the U.S. president said. On the campaign trail, Trump would boast that his negotiating skills would put a stop to the Ukraine war within 24 hours of him taking office. But so far he's been frustrated at the slow progress. A breakthrough meeting that was to take place in Turkey earlier this month, ended up not happening at the leader level as Putin refused to show up. Trump later said that Putin didn't fly to Turkey because the U.S. president wasn't going, as Trump was scheduled on his trip to Saudi Arabia, Qatar and the United Arab Emirates. Trump then got on the phone with Putin the following Monday. During his Sunday night post on Truth Social, Trump continued to blame the war on his predecessor. 'This is a War that would never have started if I were President,' he claimed. 'This is Zelensky's, Putin's, and Biden’s War, not "Trump's."' 'I am only helping to put out the big and ugly fires, that have been started through Gross Incompetence and Hatred,' the president said.