The Dow closed above 29,000 for the first time Wednesday, with investors cheered by the U.S. and China signing a preliminary deal that eases, if not ends, the fierce two-year trade fight between the nations.

President Donald Trump and China's chief negotiator, Liu He, signed the "Phase 1" agreement before a group of corporate executives and press at the White House. The pact eases some sanctions on China. In return, Beijing has agreed to step up its purchases of U.S. farm products and other goods.

The Dow added 91 points, or 0.3%, to close at a record high of 29,031, finally passing the 29,000 mark it had flirted with since the start of year. The broader S&P 500 and tech-heavy also scaled new heights Wednesday.

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Despite the agreement, Wall Street analysts cautioned that trade tensions are likely to remain.

"The fragile truce brought by the 'Phase-one' trade deal should prevent a further escalation of China-U.S. tensions ahead of the 2020 elections," Gregory Daco of Oxford Economics told investors in a report. "However, while the deal is a step in the right direction, further tariff rollbacks should not be expected until after the elections, and broken promises could lead to tariffs snapping back in the coming months."

China's tall task

One reason caution is warranted: Hundreds of billions in U.S. tariffs will remain on Chinese goods as talks continue. In the meantime, both sides will have to deal with some of the more contentious trade issues as they move ahead with negotiations.

Skeptical analysts also question if Beijing can adhere to key commitments under the deal, with PNC Financial Services Group senior economist Bill Adams questioning if China will reach the targeted amounts for purchases of U.S. farm and energy products.

Nicole Cohen, an Asian specialist with McGuireWoods Consulting, noted that the deal doesn't resolve major issues that spurred Mr. Trump to levy heavy new tariffs on China. Those include forced technology transfers by U.S. companies to Chinese enterprises and China's massive subsidies for emerging sectors, such as robotics, clean energy and artificial intelligence.

"Without addressing the broader conflict with respect to emerging technologies, the trade deal kicks the can a little further down the road," Cohen said.

More positively, the agreement allows Wall Street to at least focus on corporate earnings reports over the next few weeks and the U.S. economy.

"If we hear a better tone this earnings season, more confidence in guidance, that could encourage investors," said Jeffrey Kleintop, chief global investment strategist at the Schwab Center for Financial Research. "That might even outweigh what the trade deal actually looks like."