Reuters reports that Vilsack - who served as USDA secretary under President Barack Obama and as Iowa governor from 1999 to 2007 - is seen by establishment Democrats as a sound choice, largely because of his moderate politics and longstanding relationships with large-scale farmers.

But Vilsack's congressional confirmation is expected to face headwinds from progressive Democrats. Critics argue Vilsack is cozy with corporate agribusiness and top lobbying groups such as the American Farm Bureau Federation and the US Dairy Export Council, where he is currently the chief executive officer.

If confirmed, Vilsack will face one of the worst American hunger crises since the Great Depression, as COVID-19 cases surge, aid runs dry and retail food prices climb.

As of the end of November, more than 25.7 million Americans over the age of 18 said they did not have enough to eat, according to the latest US Census' weekly pulse survey.

"It is vital that we have experienced leaders who can hit the ground running" to address food insecurity, produce industry group United Fresh said on Wednesday 9 December.

It was not immediately known when Biden would nominate Vilsack. The two sources familiar with his decision spoke on condition of anonymity.

Vilsack's spokeswoman, Regina Black, declined to comment. The Biden transition office did not immediately respond.

Farmers express both relief and worry

For many Midwestern crop farmers, Vilsack - who owns farmland with his wife in Iowa - is considered one of their own. He leased the farm during his tenure with the Obama administration.

Vilsack was applauded on 9 December by producers in Midwestern states which produce the bulk of commodity crops like corn, soybeans and wheat - and where rural voters backed Republican President Donald Trump.

One of their key fears: a revival of Obama-era environmental regulations, such as the Waters of the United States (WOTUS) rule, which broadened the definition of waterways under Environmental Protection Agency authority. The rule, challenged in court, was ultimately scrapped by Trump.

"I'm really glad to see somebody from agriculture fill it," said Roger Cerven, 58, a fifth-generation farmer who grows corn and soybeans in southeastern Iowa. "I am not quite as concerned about what rules and regulations that could come down."

The US Farm Belt was battered by Trump's trade war with China and waivers exempting oil refiners from mixing corn-based ethanol. But Midwestern farmers also received unprecedented direct farm subsidies under Trump, even as coronavirus stimulus for millions of other Americans stalled in Congress, helping him maintain broad support.

The USDA oversees billions of dollars in farm support programmes, as well as food programmes for schools and families in need. Critics of large-scale agribusiness say its leadership needs to better reflect global environmental changes and the country's growing economic and racial diversity.

From cattle ranchers and dairy operators, to fruit and vegetable growers, backlash against such corporations and powerful agriculture lobbyists has mounted in recent years, as producers argue that Washington has ignored the needs of small-scale and minority-owned farms.

Biden's pick also has been criticized by activists who had hoped to see an agriculture chief who would emphasise environmental and nutritional concerns - specifically US Representative Marcia Fudge of Ohio, who would have been the first Black woman to fill the role.

“If (Vilsack) is confirmed, a lot of eyes will be watching to make sure the USDA truly exits the Trump era and starts taking responsibility for protecting human health and the environment,” said Brett Hartl, government affairs director at the Center for Biological Diversity.

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