Russia and the United States have failed to agree on terms for Russia joining the World Trade Organization, as the annual G8 summit begins.
The two leaders reached agreement on global nuclear energy
Russian President Vladimir Putin had hoped for a deal that he could announce after a bilateral meeting with President Bush earlier in the day.
Mr Bush said there had been progress, but still no deal.
The leaders met prior to the official opening of the summit, which is being held in St Petersburg.
On Saturday evening, leaders of the G8 nations opened the summit with an informal dinner.
Formal talks on energy security and the crisis in the Middle East will begin on Sunday morning.
Mr Bush and Mr Putin met on Saturday as other leaders were due to arrive.
The Russian Trade Minister, German Gref, said that agriculture was the main remaining obstacle to Russia gaining entry to the WTO.
BBC economics correspondent Andrew Walker says the issue is the way that Russia restricts imports of food on health grounds.
G8 SUMMIT: 15-17 JULY
The world's seven richest nations - the US, Japan, Germany, France, Britain, Italy and Canada have met annually since 1975
Russia joined in 1998, turning the G7 into the G8
2006 summit to be held in St Petersburg - the first time Russia has hosted the G8
Energy security, infectious diseases and education are on Russia's agenda
Mid-East crisis, Iran, North Korea and international terrorism are also likely to be discussed
American negotiators want to be sure that it is not done arbitrarily and that Russia's procedures are consistent with WTO rules.
However, the two leaders made progress on some other contentious issues, including access to Russia's banking and insurance markets and the enforcement of Russian laws against the piracy of music, computer programs and DVDs.
American officials hope that a deal can be done in the next few months.
Speaking after the talks, the two leaders said they had reached agreement on global nuclear energy, and fighting nuclear and other forms of terrorism.
On the violence in the Middle East, Mr Bush called on Hezbollah to lay down its arms while Mr Putin called for a "balanced" use of force in the Israeli-Lebanese crisis.
Despite a thaw in the run-up to the summit, relations between the US and Russia have been frosty over recent months.
Mr Bush has pledged to raise concerns about freedom in Russia during their meetings but said he would not lecture Mr Putin.
President Putin recently accused Western critics of Russian democracy of using "colonialist" rhetoric and said they should not interfere in Russia's affairs.
Seven of the G8 nations, uneasy about the increasing role that Russia will have in meeting their energy needs, want energy supplies to be secure, says our economics correspondent.
Russia in turn wants its customers to be secure.
The BBC's Jonathan Marcus in St Petersburg says a resurgent Russia is eager to play a role on the world stage and the G8 summit provides just such a platform for Mr Putin.