Rio Tinto has been fighting a bid from BHP Billiton
Takeover target Rio Tinto has said that its production levels in the first three months of 2008 show it should not give in to a rival's hostile bid.
The Anglo-Australian giant reported record iron ore sales and said output of aluminium was at an all-time high.
This performance showed its desire to "deliver faster, better and smarter than our competitors", it said.
In February, Rio rejected a $147bn (£74.8bn) offer from BHP Billiton - which BHP has said it will not improve.
Rio's chief executive Tom Albanese said that commodity markets - which have been driven by demand from China and India - remained strong, with prices for many products at record highs.
This backed the firm's view that the US slowdown would have "little effect on global metal and mineral supply and demand balances", he said.
"Our value as an independent business is far in-excess of what BHP has proposed and we're superbly placed for the future," Mr Albanese added.
Rio Tinto made a $7.44bn (£3.8bn) profit for 2007 - 1% higher than a year before - on the back of surging commodity prices.
At the time, analysts said that the results left Rio well placed to fend off a hostile bid from rival BHP Billiton.
BHP's bid offered 3.4 of its shares for each Rio share. This was higher than the previous informal three-for-one proposal, worth $130bn, that was first announced in December of last year.