Greenback is being offered in Asia ahead of Brexit vote and amid rising oil prices and that is helping NZD/USD approach one-year high set yesterday at 0.7188 levels.Focus on Brexit pollsRisk sentiment picked up pace after latest round of Brexit polls showed an overall lead for the ‘remain’ vote. The kiwi is benefitting from the same as well as from the higher oil prices.Caution is advised as the broader market sentiment is at the mercy of Brexit. Polls open at 6 GMT and the volatility could pick up in London session and remain elevated till Friday’s NY closing. Economic data releases in the US- weekly jobless claims – are likely to take a backseat ahead of poll results due tomorrow between 3 GMT to 6 GMT. NZD/USD Technical LevelsThe pair trades around 0.7175 levels. The immediate resistance is seen at 0.7188 (previous day’s high), above which prices could attempt 0.7275 (Mar 18, 2015 low). Further gains could run into resistance at 0.73. On the other hand, a breakdown of support at 0.7153 (channel support), under which the pair could test psychological support of 0.71. A violation there could yield 0.7054 (Apr 19 high).