China is edging toward what could be its first credit downturn in decades, as personal-loan delinquencies in the country climb during the coronavirus pandemic.

In recent weeks, executives at some Chinese banks and online lending platforms said more consumers have fallen behind on their credit-card and loan payments, which could snowball into higher defaults in the coming months. Some lenders have reduced loan originations as a result, despite regulators’ calls to keep credit flowing across the economy.

The development could foreshadow what is in store for U.S. banks and internet lenders in the coming months, as millions of people stay home and struggle with reduced incomes.

“Individuals’ willingness and ability to repay loans have both declined,” said Tian Huiyu, president of China Merchants Bank , during an earnings call last month. The lender is one of China’s biggest issuers of credit cards and has a sizable retail business.

Mr. Tian said delinquencies on credit-card debt, mortgages and micro loans increased significantly in February, during a near-nationwide shutdown of many business operations and quarantine measures that kept much of the country’s population at home.