Spot gold faces resistance at $1,830/oz - analyst Dollar hovers close to one-month low marked on Friday U.S. will "respond decisively" if Russia further invades Ukraine - Biden Jan 3 (Reuters) - Gold scaled a six-week high before it gave up gains to trade flat on Monday, as safe-haven buying fuelled by an Omicron-driven surge in COVID-19 infections countered pressure from higher U.S. Treasury yields. Spot gold was little changed at $1,826.58 per ounce by 0313 GMT, after hitting it highest since Nov. 22 at $1,831.49 earlier in the session. U.S. gold futures were down 0.1% to $1,826.70. "Gold prices would not free-fall as real rates and real yields would remain very close to zero until the coast is all clear from the strains of COVID-19," Phillip Futures analyst Avtar Sandu said in a note. Continued focus on the Ukraine border with Russia had brought investors" interest back to gold as a safe haven, and a weaker dollar provided further support to the metal, he added. Benchmark 10-year U.S. Treasuries ended 2021 with the largest yield increase since 2013. Higher yields raise the opportunity cost of holding non-interest paying gold. The U.S. dollar index (.DXY) held close to one-month lows touched last Friday, boosting gold"s demand by making the metal cheaper for buyers holding other currencies. Over 4,000 flights were cancelled around the world on Sunday, with more than half of them U.S. flights, adding to the toll of holiday week travel disruptions due to adverse weather and the surge in COVID-19 cases. read more U.S. President Joe Biden told Ukraine"s President Volodymyr Zelenskiy that the United States and its allies would "respond decisively" if Russia further invades Ukraine, the White House said in a statement. read more Spot gold faces a resistance at $1,830 per ounce, and it may hover around this level or retrace towards a support at $1,815, according to Reuters" technical analyst Wang Tao. Spot silver shed 0.5% to $23.15 an ounce, platinum gained 0.4% to $966.00, and palladium rose 0.4% to $1,899.81.