One piece read: “Trump has always blamed China for the loss of U.S. jobs, but most economists believe that it is automation, rather than China or Mexico, that are responsible for U.S. job losses.”

This week, the United States began imposing tariffs on $200 billion worth of Chinese imports, the biggest round of levies to take effect in an escalating trade war that both sides say could last a long time.

Republican Party officials in Iowa have expressed concerns about layoffs and financial losses resulting from the tit-for-tat tariffs. Some Republicans fear the trade war could depress turnout in the November elections, when the party is in danger of losing control of the House and possibly the Senate.

As Chinese officials have tried to figure out a strategy for dealing with the tariffs, some have suggested that China should stay quiet until after the elections, arguing that Mr. Trump would have less support in Congress once the Democrats control the House.

Analysts in China said that Mr. Trump’s troubles in Iowa were not a good enough reason for China Daily to publish the supplement and only left the impression the country is trying to influence the elections.