Asian shares firmed slightly in early trade with technology stocks resilient after generally upbeat earnings despite weakness in the global smartphone market and concerns about more regulation.

Oil prices stood near their highest since late 2014 on Tuesday, ahead of an announcement by US President Donald Trump on whether he would withdraw from a landmark nuclear deal with Iran, which fuelled concerns about crude supply.

US West Texas Intermediate (WTI) crude futures on Monday rose above $70 for the first time since November 2014, having gained more than 18 per cent from this year's low touched in February. Oil prices later pared some of those gains as traders took profit after Trump confirmed in a tweet that he would announce his decision on the nuclear deal at 1800 GMT on Tuesday.

“The oil market has priced in the high likelihood of Trump withdrawing from the nuclear deal with Iran. If he is going to impose sanctions similar to those the US had in 2012, that would likely to cause a shortage in oil,” said Tatsufumi Okoshi, senior commodity economist at Nomura Securities.

In addition, falls in Venezuelan oil production due to problems at the country's oil company PDVSA also added to the rally. US crude futures last traded at $70.04 per barrel, down 1.0 per cent from Monday's settlement price.

Global benchmark Brent crude futures stood at $75.62 per barrel, down 0.7 per cent, having risen as high as $76.34 on Monday. While caution on Trump's statement kept many investors on edge, Asian shares made small gains, led by technology firms.

MSCI's broadest index of Asia-Pacific shares outside Japan gained 0.2 per cent, with information technology shares rising 0.4 per cent. Japan's Nikkei was almost flat. On Wall Street on Monday, the S&P 500 gained 0.35 per cent, boosted by Apple's sixth straight day of gains.

Currency markets

In currency markets , the dollar broadly held firm on the prospect of solid US economic growth, helped partly by Trump's tax cuts and spending, pointed to further rises in US interest rates down the road. That prompted investors to buy back dollars they had sold earlier this year on worries about Trump's protectionist trade policies.

The euro hit a four-month low of $1.1897 on Monday and last stood at $1.1924. Against the yen, the dollar stood little changed at 109.07 yen, off its three-month high of 110.05 yen.

The combination of higher oil prices, a strong dollar and higher US rates is risky for some emerging market assets as it could significantly worsen their trade balance and also encourage investors to shift funds to higher-yielding US assets.

JPMorgan's emerging market bond index hit the lowest level in more than a year.

The Indian rupee hit a 15-month low while the Indonesian rupiah hit its lowest level in 2-1/2 years on Monday. The divergence between developed and emerging markets was also visible in equity prices. Brazil's Bovespa hit three-month lows while Germany's Dax hit three-month highs and Italian shares hit 8-1/2-year highs.

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