Ministers are meeting for a further round of talks in an effort to agree a way forward for a global trade deal.
Mr Mandelson says Europe has tabled the best offer it can
The talks in Geneva hope to find a breakthrough in the key areas of farm and industrial goods.
Without a deal, the World Trade Organization (WTO) will not be able to complete its so-called Doha round by its end of year deadline.
For the past six months talks have stalled as the US and Europe defended calls for tariff and subsidy cuts.
As well as demanding lower tariffs for manufactured goods, the EU also wants developing countries to free up their trade in services such as IT and finance.
Ahead of the meeting, WTO chief Pascal Lamy called on the ministers to take urgent action.
"We need big political decisions to be taken now," he told the BBC.
But while Europe's trade minister Pater Mandelson has called for more to be done, he is currently standing firm, saying the EU will only improve its offer if "others show a similar flexibility and willingness to go further".
Instead he insists the US must improve its offer to cut domestic farm subsidies.
Meanwhile, developing nations such as India and Brazil insist they cannot take any action on industrial goods if questions remain on agriculture.
However, diplomats are not expecting much movement by the end of the latest negotiations.
"I do not think we can do a full... deal," former Canadian trade envoy John Weekes said.
"The best we can get is maybe some progress on key issues that could be the spark that allows the rest to happen."