ANZ analysts said dollar strength has hit investor demand, leaving copper slightly lower in European trade. The spot premium over three-month copper narrowed, suggesting supply tightness may be easing, although global copper stocks continue to fall. Market nervousness persists ahead of a White House plan on tariffs for refined copper imports; tariff concerns have driven large copper flows into the US in recent months. LME three-month copper fell as much as 0.3% to $14,219/tonne.