Russian President Vladimir Putin (R) shakes hands with United States President George W. Bush at a press conference following their meeting in St. Petersburg, July 15, 2006. Putin held talks with Bush on issues including the Middle East crisis, the Iran nuclear issue, and Russia's bid to join the World Trade Organization on Saturday. (Xinhua Photo(Xinhua Photo)

    ST. PETERSBURG, Russia, July 15 (Xinhua) -- The nuclear agreements reached at a meeting between the U.S. and Russian leaders and their failure to iron out differences on how to tackle escalating Mideast violence and on a trade deal reflect the complexity of the bilateral relations.

    Following talks in St. Petersburg, the presidents of the United States and Russia announced an agreement on cooperation in nuclear energy and another on launching a joint initiative to combat nuclear terrorism.

    The Global Initiative to Combat Nuclear Terrorism calls on countries to improve accounting, control and physical protection of nuclear material and radioactive substances as well as the security of nuclear facilities, and prevent acts of nuclear terrorism.

    Both sides also committed themselves to strengthening the global non-proliferation regime, and the two leaders agreed on the creation of international centers for uranium enrichment and reprocessing of spent nuclear fuel.

    Russia could reap big economic gains from a potential agreement on storing spent nuclear fuel, analysts said.

    U.S. President George W. Bush, in the town for the annual Group of Eight summit that opened on Saturday, and his Russian counterpart Vladimir Putin met amid a recent flare-up in violence in the Middle East. Both leaders urged a halt to the violence.

    But the two differed sharply on who was to blame for the escalation of tensions between Israel and Lebanon, with Bush blaming Hezbollah and Putin stressing that the use of force should be balanced and should stop.