“Growth is harder to come by these days, and that is why lots of countries now are focusing more on reforms,” said Samy B. Muaddi, an emerging markets bond manager at T. Rowe Price. The fund also upgraded its economic forecast for the eurozone, projecting growth of 1.6 percent in 2015. Economists cited the renewed sense of optimism surrounding the European Central Bank’s commitment to buy government bonds as a means to stimulate economic activity. The relatively positive outlook for Europe contrasts with the fund’s comments on Europe last fall when it took Germany to task for not doing more to jump-start a recovery in Europe.

Now there are strong signs of increased bank lending and economic activity in Germany, Spain and even Italy, where the policies of the new prime minister, Matteo Renzi, are having a positive effect.

With the United States set to grow at 3.1 percent this year and next, the fund said that the large developed economies would need to assume a dominant role in driving global growth. Low interest rates and lower oil prices would help, economists said.

The fund said that the dollar’s recent strong run could add half a percent to global growth, with the stimulative effect of weaker currencies in Japan and Europe prevailing over reduced exports in the United States.

Still, as equity markets hit new highs, lifted by a wave of large-scale corporate deal making, more economists are coming around to the view that the American economy is strong enough to absorb an expected increase in interest rates this year by the Federal Reserve.

“The U.S. economy is in very good shape,” said Rick Rieder, a senior bond executive at the asset management giant BlackRock, citing the 250,000 jobs the economy has created in some months.

Whether Greece can strike a deal with its creditors before running out of money will be a major topic of discussion this week. Many of the main players — including the Greek and German finance ministers, Mario Draghi of the European Central Bank, and Jeroen Dijsselbloem, who represents European creditors — will be in town this week.