MOSCOW, March 28 (Reuters) - Russian Foreign Minister Sergei Lavrov on Monday said Russia's relations with China were at their strongest level ever, at a time when Western nations are seeking to isolate Moscow with unprecedented sanctions over Ukraine.

Beijing has repeatedly voiced opposition to the sanctions, insisting it will maintain normal economic and trade exchanges with Russia, and has refused to condemn Moscow's actions in Ukraine, but the government is wary of Chinese companies running afoul of sanctions.