By Gregor Stuart Hunter

SINGAPORE, June 16 (Reuters) - Asian stocks inched up on Tuesday after rallying on the previous session on news of a peace deal between Iran and the U.S., as investors turned their focus to several central bank decisions including an expected rate hike from the Bank of Japan.

Early trading in the region followed a familiar pattern, with markets settling into a more measured tone on Gulf developments as the initial excitement over the preliminary agreement between Washington and Tehran began to fade.

Oil prices, which settled at a three-month low overnight, reflected the cautious stance, with Brent crude futures LCOc1 up 51 cents, or 0.6%, at $83.74 a barrel. Shippers in Asia and Europe said rebuilding confidence in resuming transit through the Strait of Hormuz could take weeks.

MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS added 0.2%, with Korean shares .KS11 leading gains. Japan's Nikkei 225 .N225 was down 0.2%, retreating from a record high as S&P 500 e-mini futures EScv1 slipped 0.1%.

While U.S. President Donald Trump's announcement of a deal with Iran drew initial investor relief on Monday, it also puts Washington on a collision course with Israel.

"While it is an important diplomatic breakthrough that should remove a key source of market volatility, the durability of the deal is likely to be tested in the future," analysts from Westpac wrote in a research note. "Many sticking points, including the fate of Iran’s nuclear programme, were left to be resolved in subsequent negotiations."

Overnight on Wall Street, stocks and bonds rallied on optimism over the deal. The S&P 500 .SPX jumped 1.7% and the Nasdaq Composite .IXIC surged 3.1%, while the Dow Jones Industrial Average .DJI and the STOXX 600 both closed at record highs.

Beyond geopolitics, traders are awaiting several major central bank decisions, including the Bank of Japan, which is set to raise interest rates to a 31-year high on Tuesday.

Deputy Governor Shinichi Uchida will hold a press briefing after the meeting, which Governor Kazuo Ueda will miss because he is undergoing medical treatment.

"We do not anticipate any major changes to the Bank’s assessment of current conditions," analysts from Mitsubishi UFJ wrote in a research note.

"We expect Deputy Governor Uchida’s press conference, including the rationale he presents for the rate-hike decision, will be based largely on Governor Ueda’s June 3 speech," the note added. "Mr. Uchida is also likely to follow the governor’s remarks when discussing future policy decisions."

The Reserve Bank of Australia will pause its tightening cycle when it meets later, according to a Reuters poll of economists.

The U.S. dollar index =USD, which measures the greenback's strength against a basket of six currencies, held steady at 99.66, firmly within the tight trading channel in which it has sat all week.

The yield on the U.S. 10-year Treasury bond was up 0.8 basis point at 4.475%. Gold XAU= was up 0.2% at $4,313.87.

In cryptocurrency markets, bitcoin BTC= was down 0.3% at $66,245.97, while ether ETH= slumped 1.2% to $1,793.70.