Insurance veteran Evan Greenberg has called on the US to “tone down rhetoric and symbolism around Taiwan” and focus on preserving peace and stability in the region, in the latest sign of how deepening geopolitical divisions are worrying corporate leaders.

Greenberg, who has built New York-listed Chubb to become one of the world’s biggest insurers, devoted part of his annual letter to shareholders to US-China relations. The chief executive called the tensions over Taiwan “the most proximate risk of conflict” for the relationship between the two superpowers, as Beijing presses its claims over Taipei and Washington encourages the island to strengthen its defences.

“We should, however, tone down rhetoric and symbolism around Taiwan,” Greenberg wrote in the letter, which was filed with regulators on Monday. “Supporting Taiwan as a demonstration of opposition to China does not improve America’s national security; it just raises China’s insecurity and feeds its impulses to overreact to Taiwan-related events.”