US President George W Bush has said he is committed to reaching an agreement over global trade and bringing to an end a deadlock with the European Union.
President Bush has been meeting European leaders
Speaking at a US-EU summit in Vienna, Mr Bush acknowledged problems, but said they could be overcome by hard work.
Global leaders will meet in Geneva on 29 June to discuss the latest round of World Trade Organization (WTO) talks.
Called the Doha Round, the talks have stalled with accusations of intransigence coming from all sides.
Later this month, the US, the EU and the G-20 group of developing countries will meet in Geneva in an effort to find enough common ground to hammer out an agreement.
"The Europeans have problems with the US position; we have problems with the European position; we both have problems with the G20 position," said Mr Bush. "But the point is, we're committed to a successful round.
"There's a ministers' meeting here at the end of this month, and my pledge to our European counterparts is, we'll do the very best we can to reach an agreement," he added.
"We can't let this round fail," he continued. "A failed WTO round would be missed opportunity."
Two of the main stumbling blocks have been agricultural trade and farming subsidies.
Speaking on the sidelines of the summit, EU trade chief Peter Mandelson warned that, despite the optimism, negotiators may still fail to reach agreement later this month.
"I can't foresee what will happen," Mr Mandelson said.
The EU has complained the US has not gone far enough in offering to cut the subsidies it offers its farmers.
The US, meanwhile, claims that it has tabled aggressive cuts that the EU has failed to match.
However, even Mr Mandelson conceded that there were some positive signs.
"That drum beat on both sides of the Atlantic is encouraging," he said. "But there is no disguising it's a political call that has got to be made at this stage, and a political call at the highest level."
The US and EU are meeting in Vienna because Austria currently holds the EU presidency.