The global economy is expected to expand to a 3.6 percent annual rate this year, up from last year's rate of 3.2 percent.
Tuesday's assessment comes from the International Monetary Fund as economic officials from the World Bank and nations around the world gather to discuss growth, jobs, worries, ideas, and pleas for action this week in Washington.
The global lender's experts say improving investment, industrial production, business and consumer confidence are helping economic expansion. The IMF says advanced nations, including the United States, will grow more slowly than developing countries.
The report puts U.S. economic expansion at 2.2 percent this year, up from 2016. IMF experts say future U.S. growth is uncertain because proposals to cut taxes and regulations and boost spending on infrastructure have not yet made their way through a divided legislature.
The outlook for China has been cut slightly, but remains strong at 6.8 percent this year.
The economy in sub-Saharan-Africa is expected to reach a 2.6 percent annual growth rate this year, and 3.4 percent next year. That is a little slower than earlier projections.
IMF officials say national leaders need to make reforms now "while times are good." They urge efforts to boost potential output, reduce inequality, and make national economies more resilient. The global lender also calls on advanced economies to keep interest rates low, at least until inflation begins to rise, and work to strengthen international economic cooperation.
The economic experts warn that commercial credit problems in China, faster interest rate increases in advanced nations, or a drastic rollback of rules intended to prevent another financial crisis could derail economic growth.