LONDON, June 9 (Reuters) - Top U.S. and Chinese officials will sit down in London on Monday for talks aimed at defusing the high-stakes trade dispute between the two superpowers that has widened in recent weeks beyond tit-for-tat tariffs to export controls over goods and components critical to global supply chains.

U.S. stock index futures were subdued on Monday as investors looked ahead to talks between the United States and China aimed at mending a trade rift that has rattled financial markets for much of the year.

The United States is looking to restore the flow of “crucial” rare earth minerals, which were restricted after China’s retaliatory efforts in early April.