Global giants the European Union and China meet at a Brussels summit on Thursday under pressure to bolster slowing economic growth and tackle tough international dilemmas.
President Vladimir Putin impressed leaders by holding an Asian summit on an island off a revamped Pacific city but the surface shimmer hid underlying problems in the Russian Far East and the country as a whole.
The United States welcomed Friday a deal to cut tariffs on dozens of "green" products in the Asia-Pacific, saying it would boost the region's economies as well as help protect the environment.
Asia-Pacific leaders gather in Russia's far east this weekend for talks aimed at promoting trade but territorial disputes and other regional tensions may cloud the event.
Secretary of State Hillary Clinton said Friday that the South Pacific was big enough for both the United States and China but urged the Asian power to ensure it distributes its growing aid fairly.
Iran's hopes of boosting its international prestige by hosting a Non-Aligned summit this week were tripped up by a critical new UN nuclear watchdog report.
A new UN atomic agency report due Thursday or Friday is expected to detail how Iran is continuing to expand its nuclear programme despite painful sanctions and talk of Israeli military action.
An emergency summit of the 57-member Organisation of Islamic Cooperation (OIC) began late Tuesday with a proposal to suspend conflict-wracked Syria, a move strongly opposed by Iran.
Rich nations and the Bill and Melinda Gates Foundation said they had pledged more than 2.6 billion dollars towards family planning in developing countries at a summit in London.
World stock markets surged Friday, the euro jumped against the dollar, and oil prices rocketed after a key EU summit delivered surprise emergency measures to fight the eurozone debt crisis.