Rubber futures fell below 200 US cents per kilogram, reaching a one-week low, pressured in part by declining oil prices that make synthetic substitutes more competitive. The move came after Treasury Secretary Scott Bessent announced that the Trump administration would support oil tankers operating in the Persian Gulf. At the same time, subdued demand from a leading buyer continued to weigh on the market. Prices had previously surged to one-year highs in late February amid concerns over supply shortages, as rubber trees entered the "wintering" season in major producing countries such as Thailand and Vietnam.