The IMF also forecast that all five of Europe's largest economies will grow even faster.
"In Washington this week I will be talking to our worldwide partners about how we can carry on increasing global economic growth, with Britain again playing an active and engaged role in the global economy".
The uptick is driven by expectations that the USA will cut taxes and higher confidence among consumers and businesses. Those and other headwinds are expected to keep world growth capped at 3.8% for the foreseeable future, according to the IMF's long-term outlook.
"The global economy seems to be gaining momentum-we could be at a turning point", said IMF's chief economist Maurice Obstfeld.
"Medium-term growth prospects are favourable, with growth forecast to rise to about eight per cent over the medium term due to the implementation of key reforms, loosening of supply-side bottlenecks, and appropriate fiscal and monetary policies", the report said. They include "the threat of deepening geopolitical tensions", the possibility that rising USA interest rates will squeeze economic growth and rattle financial markets and the threat that protectionist measures will damage global trade.
Investor sentiment in US growth is reliant in part on the Trump administration delivering on promises of a tax overhaul and infrastructure spending, though the president has hit speed bumps advancing his agenda.
Global trade has fostered "economic miracles" around the world, driving growth and lifting millions out of poverty, he stressed.
It credits improving manufacturing and trade in bigger economies for the 3.5 percent growth it now expects, up from January's 3.4 percent forecast. They also expect President Donald Trump to deliver tax cuts and infrastructure spending that could help boost USA economic growth.
The IMF also lauded the Philippines's efforts to drive its high-growth numbers back to the masses.
"This will increasingly make it more hard to transition to a consumer economy if households are already that indebted". The IMF believes euro zone growth will then slow to 1.6% in 2018.
The IMF's World Economic Outlook (WEO), released on Tuesday, raised its projection for global growth in 2017 to 3.5%, up from 3.4%.
On the threat of protectionism, however, which the International Monetary Fund has launched a campaign against in the past week, Shah was less concerned.
"One salient threat is a turn toward protectionism, leading to trade warfare", Obstfeld said, adding this "would result in a self-inflicted wound that would lead to higher prices for consumers, lower productivity and therefore, lower overall real income for households".
So far, however, Mr. Trump's team has shown itself in the trade arena to be less aggressive than some feared.
While the Netherlands rejected such an approach earlier this year, the same feelings are thought to have helped drive the UK's Brexit vote and United States president Donald Trump's ascension to the Oval Office.