Iron ore has rebounded above $US60 a tonne for the first time since early March, after logging a nearly 4 per cent gain on Wednesday.

In continuing good news for the beleaguered mining sector, iron ore delivered to the Port of Qingdao rose $US2.19, or 3.7 per cent, to $US60.89.

The jump consolidated several days of smaller gains that have seen the commodity recover from a fall to $US56.18 on April 30, ahead of China's May Day holiday break.

However, UBS has suggested prices could resume their fall and plumb the depths of $US45 per tonne in the second half of the year.

Iron ore has now gained more than 29 per cent since early April when it was trading as low as $US47.08.

The dramatic turnaround has been fuelled in recent weeks by BHP Billiton's decision to slow its rate of production growth.

BHP's and Rio Tinto's strategy of ramping up production and squeezing the price of iron ore has led to a war of words between the two miners and Fortescue Metals Group chairman Andrew Forrest.

Mr Forrest has attracted support from political leaders in his criticism of the strategy. However, investors have shown little sympathy for the billionaire's plight.

BHP has also continued to stoke tensions with its iron ore presidentJimmy Wilson accusing Fortescue of being "the world's most prolific iron ore growth story" in a memo to more than 11,000 staff.

Rio chairman Jan du Plessis, meanwhile, weighed into the debate on Thursdaytelling The Australian Financial Review that the miner "derives no enjoyment" from the pain being felt across the mining sector because of iron ore's price collapse.

SUPPLY CUTS 'NOT SUFFICIENT'

A report by UBS suggests iron ore shipments from Australia are set to pick up in the second half of the year on mine expansions from the largest suppliers. UBS is forecasting prices might drop as a consequence to average $US45 a tonne between July and December.

While some higher-cost supply is being cut, including from Atlas Iron, growth in output will continue, the bank said in the report. Rio Tinto's next 60 million tonnes a year might come on line from the second half, and BHP Billiton is still moving toward capacity of 270 million tonnes a year from an estimated 260 million tonnes, according to the bank. The new Roy Hill mine may also start shipments, it said.

"We anticipate growth in export volumes through 2015, particularly in the second half, as new capacity from Rio Tinto, Hancock Roy Hill and ongoing asset optimisation from BHP Billiton allow increased shipments," UBS said in the report. "Recent cuts help, but the market is expected to remain in an albeit-smaller surplus over the medium term."

Rio will meet shareholders in Perth on Thursday at its annual meeting.

Exports from Australia, the world's biggest shipper, climbed about 5 per cent in March from February to 61.4 million tons, UBS said, citing figures from the Australian Bureau of Statistics. Overseas sales surged to 716.7 million tons last year from 582.8 million in 2013, it said. The bank forecasts that the country's exports may total 809 million tons in 2015.

"Supply cuts are not sufficient to drive higher prices when operators are cutting costs, and as demand remains weak," UBS said.

Risks to consumption remained in China, where the property sector is under pressure, it said. The bank's report covered an analysis of Australia's bulk-commodity shipments in March and, separately, looked at iron ore supply and costs.