Asian shares mixed, oil steady as US tightens Iran sanctions

Asian shares were mostly lower Tuesday after U.S. stocks drifted to a mixed finish, while oil prices held steady following new U.S. sanctions against Iran. Regional benchmarks traded in a narrow range with U.S. futures nearly unchanged. Tokyo's Nikkei 225 gained 0.4%, while South Korea's Kospi fell 0.4% and Hong Kong's Hang Seng lost 0.3%. On Monday, the S&P 500 slipped 0.3% as tech stocks led declines, with Nvidia sinking 2.9% ahead of its quarterly earnings report Wednesday. The 10-year Treasury yield eased to 4.71% after the Treasury Department announced increased buybacks, though analysts say this won't solve fundamental issues of government debt and high oil prices. Brent crude traded near $90.51 per barrel, well above pre-war levels.