Vivek Ramaswamy, the wealthy entrepreneur seeking the Republican Party’s presidential nomination, has stopped spending money on cable television ads, a campaign representative said on Tuesday.

With just weeks to go until the Iowa caucuses kick off the voting for the nomination, Mr. Ramaswamy’s campaign is maintaining its total advertising outlays, Tricia McLaughlin, a spokeswoman for the campaign, said. However, it is shifting away from traditional television toward other methods of voter outreach for a “higher return on investment,” she added. NBC News first reported the campaign’s halt in TV ad spending.

“We’re just following the data,” Ms. McLaughlin said in a statement, adding that “we are focused on bringing out the voters we’ve identified — best way to reach them is using addressable advertising, mail, text, live calls and doors to communicate with our voters.”

She pointed out the huge sums that have already been sunk into the presidential campaign, saying that “$190 million in traditional advertising has been spent in this race nationally. Polls have barely changed.”

It is nevertheless an abrupt shift in strategy for Mr. Ramaswamy’s campaign, which has spent millions on advertising. The Ramaswamy campaign reserved about $1 million in television ads in Iowa last month — nearly double what his campaign and an allied super PAC spent in the prior month.

But Mr. Ramaswamy has struggled to make headway in Iowa, despite the intense spending and a packed schedule of campaign appearances. He estimated to reporters last month that he had spent around $20 million on his run to that point.

He maintains a distant fourth place in state polls, with less than 10 percent support. His approval ratings among Republicans nationally have also steadily declined since September, and his disapproval ratings among all Americans hit a new peak in national polls.

He has recently pushed right-wing conspiracy theories in campaign appearances. He has called the Jan. 6, 2021, attack on the Capitol an “inside job,” claimed that the 2020 election was stolen by “big tech” and suggested that the “great replacement theory” was Democratic policy.

Ms. McLaughlin noted that the Ramaswamy campaign would continue to field some ads through digital television providers — for example, YouTube TV.