France, Nov. 13 -- Top diplomats from the Group of Seven industrialised democracies presented a united front on Ukraine and Sudan on Wednesday, even as they skirted around the more contentious issues overshadowing the gathering.

Meeting in the Canadian town of Niagara-on-the-Lake - just a short hop from the US border - G7 foreign ministers held talks with their Ukrainian counterpart as Kyiv braces for what could be its most challenging winter yet.

Rolling blackouts triggered by Russian aerial attacks have underscored the fragility of Ukraine's energy grid, and Foreign Minister Andriy Sybiha made no attempt to play down the scale of the challenge.

Ukraine, he said, needed the full support of its partners to withstand a "very difficult, ...