Former Vice President Joe Biden knocked President Donald Trump's trade policy Thursday even as he argued the U.S. needs to curb China's "abusive" economic behavior.

The 2020 Democratic presidential candidate slammed Trump for tariffs on Chinese goods that sparked retaliation from Beijing and pain for American farmers. Still, he called for the U.S. to "get tough on China" — taking a more aggressive stance than he did when he downplayed the threat China poses earlier this year.

"President Trump may think he's being tough on China. All that he's delivered as a consequence of that is American farmers, manufacturers and consumers losing and paying more," Biden said during a speech outlining his foreign policy plans at the Graduate Center at the City University of New York. "His economic decision-making is so shortsighted and as shortsighted as the rest of his foreign policy."

Biden said the U.S. needs to act to counter China or it will "keep moving and robbing U.S. firms" of technology and intellectual property. But the former vice president — who supported the North American Free Trade Agreement and Trans-Pacific Partnership free trade deals that some of his Democratic rivals oppose — called for "new rules" and "new processes" to craft trade relationships.

Biden, who has led most early primary polls, called to "build a united front" of economic partners to hold China accountable.

"China can't afford to ignore half the global economy if we're united. That gives us substantial leverage to shape the future rules of the road on everything from the environment to labor to trade to technology to transparency," Biden said.

In a statement, Trump campaign spokeswoman Kayleigh McEnany said the president "has repeatedly advocated for the American worker on the world stage by taking on unfair trade practices across the world." She cited Trump's replacement for NAFTA, called the United States-Mexico-Canada Agreement, his decision to leave TPP and his China policy. She argued Biden "has a history of blue collar betrayals."

Few Democratic candidates have targeted Trump over his trade policy. But Biden previously slammed him in the key agricultural state of Iowa — which will hold the first Democratic nominating contest in February. Sen. Bernie Sanders, I-Vt., criticized Biden earlier this year for questioning how much of a threat China posed to the U.S.

Trump's trade conflict with China has raised fears about damage to U.S. businesses, farmers and the broader global economy. Trade is a thorny issue for 2020 Democratic candidates. Contenders such as Sanders and Sen. Elizabeth Warren, D-Mass., agree with Trump that free trade has harmed American workers and sapped manufacturing jobs.

Biden has typically supported U.S. trade policy. But he said Thursday that "there's no going back to business as usual on trade with me." His comments come as Democrats express reservations about Trump's NAFTA replacement due to concerns about labor and environmental protections and pharmaceutical prices.

The remarks also come as the U.S. scrambles to strike a trade deal with China. The Trump administration has slapped tariffs on $250 billion in Chinese goods during the ongoing trade war. China has responded with duties on $110 billion in American products.

Washington and Beijing restarted talks in recent weeks after efforts to strike a deal stalled. But earlier Thursday, Trump said China is "letting us down" by not buying more agricultural products. The Trump administration has considered farm product purchases to be a key part of moving forward with discussions.

Biden made the comments Thursday during a broader speech about his foreign policy strategy. He also criticized the president for favorable comments about authoritarian leaders and tweeted threats of military force.

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