Trump’s threats of secondary tariffs are “never going to go anywhere” as long as he is unwilling to impose costs on Moscow directly, Keir Giles, a senior fellow at the London-based Chatham House think tank, told NBC News Monday.

Russia continued its nightly bombardment of Ukrainian cities overnight into Tuesday, after President Donald Trump said the U.S. would send military equipment to Kyiv.

The US president says he is "disappointed" in Putin and will be sending "top-of-the-line" weapons to Ukraine, via Nato.