Confronting China on its unfair trade practices will be a "key priority" in his administration, United States President-elect Joe Biden said on Friday as he introduced veteran trade lawyer Katherine Tai as his choice for the nation's top trade envoy and adviser.

The 45-year-old Ms Tai, who is the chief trade counsel on the House of Representatives' Ways and Means Committee, worked for the Office of the US Trade Representative (USTR) from 2007 to 2014.

During this time, she rose to become the chief trade enforcer against unfair trade practices by China from 2011 to 2014, roping in trade partners to successfully bring cases against China in the World Trade Organisation (WTO).

"She understands that we need to be more strategic in how we trade - in a way that makes us all stronger and leaves no one behind," said Mr Biden, adding that Ms Tai will work closely with his economic, national security and foreign policy teams.

If confirmed by the Senate, Ms Tai will be the first Asian American in the USTR post.

Beyond her solid credentials and sophisticated understanding of trade issues, Ms Tai also "embodies a powerful immigrant story of America", said Mr Biden.

Her parents were born in mainland China and grew up in Taiwan. They moved to the US as graduate students in the sciences in the 1960s, following immigration reforms that enabled a wave of Asian migrants going to the US.

Ms Tai's father became a researcher at the Walter Reed National Military Medical Centre in Maryland, helping the US army advance treatments for American troops who fought in the Vietnam War, said Ms Tai on Friday after being introduced by Mr Biden.

She added that her mother still works at the National Institutes of Health, the US government's medical research centre, developing treatments for opioid addiction.

Her parents became naturalised American citizens in 1979, five years after Ms Tai was born in Connecticut. She was "the very first American in our family", she said.

Ms Tai, a Yale and Harvard graduate, speaks fluent Mandarin and taught English for two years at Zhongshan University in Guangzhou, China, in the late 1990s.

Trade watchers said that Ms Tai will have the stomach and the expertise to confront China. But her past record suggests she may do so in a way different from the Trump administration: under the umbrella of multilateral organisations and together with partners.

"Tai will be entirely comfortable in aggressively confronting China when needed," Mr Stephen Olson, a research fellow at the Hong Kong-based Hinrich Foundation and a former US trade negotiator, wrote in an online commentary.

He expected the Trump administration's tariffs on Chinese goods to remain in place at least initially, as Ms Tai directs the Office of the USTR to conduct a thorough review of the phase one agreement that marked something of a ceasefire to the US-China trade war.

"She has also expressed comfort with subsidies and incentives to reduce US over-reliance on Chinese imports," added Mr Olson.

During her time in the Office of the USTR, the US brought a number of cases against China in the WTO.

One notable victory involved the US challenging China's quotas on exports of rare earth minerals, which are critical to making tech gadgets such as iPhones and are supplied primarily by China.

Ms Tai was credited with bringing a number of countries on board to join the US in the rare-earths case against China, including Canada and Japan, as well as the European Union.

China dropped the quotas in 2015, following the WTO's ruling against it in 2014.

As the Democrats' trade lawyer, she was instrumental in negotiating with the Trump administration to work tougher labour and environmental protections into the US-Mexico-Canada Agreement, which was passed with strong bipartisan support last year.

This was a demonstration of her ability to find common ground between moderates and progressives, wrote Mr Olson, who added that her talent in threading the needle on difficult compromises would take on greater importance as the Biden administration navigates tricky domestic politics.

"She not only brings trade expertise to the job, but an ability to problem-solve with all sides of the political spectrum. Those skills will be needed as we navigate a post-Trump trade policy," wrote former acting deputy USTR Wendy Cutler on Twitter.

Said Mr Biden: "She's earned praise from lawmakers of both parties and from both labour and business as well. Now that's a feat."

Addressing Ms Tai, he added: "I've got more calls complimenting me on your appointment than you can imagine."