At noon AEST on Wednesday, the benchmark S&P/ASX200 index was up 36 points, or 0.46 per cent, to a one-week high of 7,860.2, while the broader All Ordinaries had climbed 39.5 points, or 0.49 per cent, to 8,120.4.
The ASX200 had earlier reached as high as 7,869.3, 41.2 points away from its all-time intraday high set on April 2.
In New Zealand, the Reserve Bank left the cash rate on hold, as expected, at 5.5 per cent.
Late Wednesday night, Australia time, the US Labor Department will release inflation data for March that could help determine the path of rate hikes in the world's biggest economy.
Hopes that the Federal Reserve will cut rates in June have fallen since last Friday's blockbuster jobs report, which far exceeded expectations.
Nine of the ASX's 11 sectors were higher at midday, with financials and tech slightly lower.
Health care was the biggest winner, up 1.3 per cent, closely followed by the materials sector.
In health care, CSL had advanced 1.4 per cent and ResMed was up 2.6 per cent.
In mining, Rio Tinto had added 2.0 per cent to a six-week high of $127.895, BHP had advanced 1.1 per cent to $45.635 and Fortescue was up 1.6 per cent to $25.67.
The big four banks were mixed, with CBA down 0.6 per cent, Westpac basically flat, and ANZ and NAB both 0.2 per cent higher.
The Australian dollar was buying 66.22 US cents, from 66.02 US cents at Tuesday's ASX close.