Britain will be the slowest growing major economy, expanding just 1.3 percent, with investment slowing "amidst continued uncertainty" about Brexit.
For the eurozone as a whole, growth is forecasted at 2.3 percent this year and 2.1 percent in 2019, a 0.2 point upgrade in each year.
Fiscal easing in Germany's coalition agreement was seen lifting growth in the euro zone's biggest economy to 2.4 percent this year (+0.1 percentage point) and 2.2 percent in 2019 (+0.3). The organization raised its growth forecast for the United Kingdom's economy to 1.3% in 2018, with a rising global recovery from the earlier forecast for 1.2%.
While broadly more optimistic than only a few months ago, the OECD warned a trade war could threaten the outlook, and forecast that United Kingdom growth would lag all G20 countries due to Brexit uncertainties.
Tax reductions and higher government expenditure reinforce the momentum in domestic demand from strong confidence, solid job creation, past gains in household wealth and the rebound in oil production, said OECD.
In 2019, the same year Britain will leave the European Union following Brexit, the forecast for growth is now set at 1.1%, lagging behind other G20 nations.
"We think the stronger economy is here to stay for the next couple of years", acting OECD chief economist Alvaro Pereira told Reuters.
According to him, in Argentina, "important reforms were made" and the estimates are favorable in the investment in construction and industry, which justifies maintaining the prospect of an increase of 3.2% in 2018 and in 2019.
The OECD says the revised outlook compares with growth of 3.0 per cent previous year in Canada. The Paris-based organization had expected growth to be 1.2 percent in 2018 and 1.0 percent in 2019.
"Macroeconomic policies are gradually becoming less accommodative, but private consumption remains robust, strong employment growth is beginning to be reflected in wages, and firmer commodity prices should boost business investment", the economic think-tank said in its interim economic outlook on Tuesday.
The statement was a veiled reference to US President Donald Trump's decision to impose tariffs without resorting to global arbitration.
Mr Pereira said a global trade war would be harmful for the global economy.