Shares on both sides of the Atlantic moved higher overnight, triggered in part by a late surge in Chinese equities, amid optimism China's government will act to support its flagging economy.
In New York trading at about 2.45pm, the Dow Jones industrial average rose 2.3 percent, the Standard & Poor's 500 Index climbed 2.1 percent, while the Nasdaq Composite Index added 2.3 percent. On Monday, US markets were closed for the Labour Day holiday.
Gains in shares of General Electric and those of Wal-Mart, last up 3.9 percent and 3.8 percent respectively, led the Dow higher. All 30 stocks in the Dow rose.
China's Shanghai Composite Index closed 2.9 percent higher.
"Concerns about a slowdown are still there, but now the market thinks the Chinese government will provide more support," John Plassard, senior equity sales trader at Mirabaud Securities in Geneva, told Bloomberg.
US Treasuries fell, lifting yields on the 10-year note seven basis points higher to 2.19 percent.