U.S. stocks climbed on Tuesday as investor concerns about rising trade tensions between the United States and China eased after Chinese President Xi Jinping promised to cut import tariffs.

The technology sector, which would be particularly exposed to a negative impact from tense trade relations with China, provided the biggest boost to the S&P 500.

Xi said China will widen market access for foreign investors, a point of contention for U.S. President Donald Trump's administration.

His comments buoyed global markets, which have been under pressure as China and the United States threatened each other with billions of dollars in tariffs.

"With (Xi's comments), we got the signal for 'risk on' in trading today," said Mariann Montagne, portfolio manager at Gradient Investments in Arden Hills, Minnesota. "That's why we've seen tech and biotech performing very strongly today."

Facebook (FB.O) shares added the most gains to the S&P 500, rising 4.5 per cent after Chief Executive Mark Zuckerberg began his testimony before Congress and took questions from lawmakers. It was the biggest one-day percentage gain for the stock in nearly two years.

Zuckerberg's testimony aimed to strike a conciliatory tone in an attempt to blunt possible regulatory fallout from the privacy scandal engulfing his social network.

The energy index had the highest percentage gain among the S&P's 11 major sectors, adding 3.3 per cent as oil broke above US$70 a barrel.

The Dow Jones Industrial Average rose 428.9 points, or 1.79 per cent, to 24,408, the S&P 500 gained 43.71 points, or 1.67 per cent, to 2,656.87 and the Nasdaq Composite added 143.96 points, or 2.07 per cent, to 7,094.30.

Only utilities and real estate, which are sensitive to interest rates, posted losses after U.S. producer prices rose more than expected in March, indicating that inflation is strengthening, which could push interest rates up further.

However, the increase in producer prices did not prompt broader concerns about future market performance.

"It's not enough to offset better expectations about the overall economy," said Kate Warne, investment strategist at Edward Jones in St. Louis.

U.S. stocks will face a major test in coming weeks as first-quarter earnings pour in. JPMorgan Chase (JPM.N), Citigroup (C.N) and Wells Fargo (WFC.N) will kick off the earnings season on Friday.

Analysts expect quarterly profits for S&P 500 companies to rise 18.5 per cent from a year ago, which would be the biggest gain in seven years, according to Thomson Reuters I/B/E/S.

Sprint Corp (S.N) shares jumped 17.1 per cent after reports that the company had restarted merger talks with T-Mobile US Inc . T-Mobile shares (TMUS.O) rose 5.7 per cent.

Advancing issues outnumbered declining ones on the NYSE by a 3.16-to-1 ratio; on Nasdaq, a 3.93-to-1 ratio favored advancers.

The S&P 500 posted six new 52-week highs and one new low; the Nasdaq Composite recorded 53 new highs and 32 new lows.

Volume so far on U.S. exchanges was 7.14 billion shares, compared with the 7.33 billion-share average for the full session over the last 20 trading days.

CANADIAN STOCKS

Canada's main stock index rose on Tuesday, led by the energy and materials sectors as reduced fears of a global trade war boosted oil prices.

The Toronto Stock Exchange's S&P/TSX composite index closed up 34.44 points, or 0.23 per cent, at 15,262.14, its second straight day of modest gains.

U.S. stocks also climbed as investor concerns about rising trade tensions between the United States and China eased after Chinese President Xi Jinping promised to cut import tariffs.

U.S. crude oil futures settled 3.3 per cent higher at US$65.51 a barrel, building on Monday's rally.

Kinder Morgan Canada Ltd (KML.TO) rebounded 3.7 per cent to $16.71 after a sharp decline the day before. The company's shareholders on Tuesday backed the pipeline operator's decision to pause most work on its Trans Mountain expansion as a way to force the Canadian government to give final approval for the project.

The energy group rose 2.4 per cent to reach its highest since Feb. 1, while the materials group, which includes precious and base metals miners and fertilizer companies, added 0.9 per cent.

The largest percentage gainer on the TSX was Ivanhoe Mines Ltd (IVN.TO), which rose 8.8 per cent, while the largest decliner was Prometic Life Sciences (PLI.TO), down 5.6 per cent.

Four of the index's 10 main groups ended higher. The TSX posted 1 new 52-week high and 5 new lows.

Canadian housing starts slowed slightly in March and building permits dipped in February, but overall residential construction activity remained strong, latest reports showed.