The United States is stepping up its campaign against China's growing presence in the Western hemisphere, where Chinese firms have been landing infrastructure and energy projects with prices that undercut American rivals. That competition has now arrived in Guyana, whose mega contracts, including the long-awaited gas-to-energy scheme, are being pursued by companies from both sides. American firms and officials argue they offer dependable delivery even when their bids cost more. Guyanese decision-makers now find themselves weighing cheaper bids against the promise of steadier execution.