US President Donald Trump has announced the US will send "top-of-the-line weapons" to Ukraine via Nato countries, while also threatening Russia with severe tariffs if a deal to end the war is not reached within 50 days.

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.

"Unlike past direct sanctions, secondary tariffs extend US reach globally, targeting Russia's trade partners. If enforced, they could affect at least 30-40 percent of Russia's oil sales, destabilizing its economy and rippling through global energy supplies," he warned.