The most-traded May iron ore contract on China's Dalian Commodity Exchange advanced by as much as 3.6% to 711.50 yuan ($112.68) a tonne, after last week's 1.8% gain.
On the Singapore Exchange, iron ore's most-active April contract rose as much as 3.2% to $141.05 a tonne.
"Any prolonged military campaign will severely impact annual iron ore exports totaling almost 70-million tonnes from Russia and Ukraine, eventually tightening the global balance," said Atilla Widnell, MD at Navigate Commodities in Singapore.
While Russia and Ukraine are not major suppliers of iron ore to China, the world's biggest steel producer, which buys most of its requirements from Australia and Brazil, exports of the material from the two nations now at war are usually sold to other European countries.
Russia's invasion of Ukraine has triggered a Western political, strategic, economic and corporate response unprecedented in its extent and coordination, with the harsh sanctions including blocking some Russian banks from the SWIFT international payments system.
