Dhaka, March 25 -- Western leaders piled on military and humanitarian aid for Ukraine on Thursday and denounced Moscow's invasion of its neighbour as "barbarism" as thousands in besieged cities sheltered underground from Russian bombardment.

At an unprecedented triple summit in Brussels, transatlantic alliance NATO, G7 rich nations and European leaders addressed the continent's worst conflict since the 1990s Balkans wars, reports Reuters.

NATO announced plans for new combat units in four eastern European countries near Ukraine, while the United States and Britain increased aid and expanded sanctions to new targets, including a woman who London said was the stepdaughter of Russia's foreign minister.

"The single most important thing is f...