(Refreshes markets through Asia afternoon, adds RBNZ comment)

By Gregor Stuart Hunter

SINGAPORE, July 8 (Reuters) - The U.S. dollar held around its highest level in a week in Asian trade on Wednesday as the U.S. and Iran traded fresh attacks, while New Zealand's currency jumped after the country's central bank lifted interest rates and flagged further tightening.

The greenback firmed 0.1% to 162.33 yen , advancing for a fourth day against the Japanese currency to reach its strongest level since July 2.

On Wednesday, Iran's Revolutionary Guards said they attacked U.S. military sites in Bahrain and Kuwait after the U.S. launched a wave of strikes against Iran in response to attacks on tankers in the Strait of Hormuz.

The greenback, widely considered a global safe haven, pared some earlier gains as the trading session progressed.

"For now, the market is keeping to the playbook that Tehran and Washington are still in a high-stakes game to gain leverage during the temporary truce, and that Tuesday’s incident would not descend back into a full-scale war," DBS analysts wrote in a research report.

"However, the incident was a reminder that the real risk remains the expiry of the interim ceasefire agreement in mid-August and the red line over transit fees in the Strait of Hormuz."

Meanwhile, the kiwi dollar jumped 0.5% to highs of $0.5705 after the Reserve Bank of New Zealand hiked rates by 25 basis points to 2.5% to curb inflation pressures, as most economists had expected, and said "some further reduction in monetary stimulus is likely to be required" to control inflation.

Its Australian counterpart strengthened 0.2% to $0.6943.

"A key argument for the hike is a concern that financial conditions would have eased further if the OCR was left unchanged," Westpac analysts wrote in a research note, referring to the central bank's official cash rate.

The euro was flat at $1.1415, while the British pound

was steady at $1.3351. The U.S. dollar index , which measures the greenback's strength against a basket of six currencies, was down 0.1% at 101.05 after earlier reaching its highest since July 2.

Brent crude was up 3.3% at $76.59 a barrel in Asian trade on Wednesday, extending a rally into a second day.

The yen crept toward a fresh 40-year low after Bank of Japan board member Toichiro Asada, the sole dissenter to the BOJ's decision in June to raise interest rates, told Reuters he must see signs of demand-driven inflation before supporting further hikes.

Bitcoin was down 1.4% at $62,797.71, while ether

declined 1.5% to $1,756.37.

(Reporting by Gregor Stuart Hunter; Editing by Stephen Coates and Kevin Buckland)