Japanese Prime Minister Shigeru Ishiba pledged Tuesday to win back public trust in his ruling party, already weakened and further damaged by his own voucher-giving scandal, while vowing to implement inflation-relief measures "seamlessly" as the House of Councillors election looms this summer.

During a press conference a day after parliament enacted a 115.20 trillion yen state budget for the just-started fiscal year, Ishiba also promised measures to ensure that people feel the effects of wage growth despite rising prices of everyday goods, though he remained hesitant about cutting the consumption tax rate on food.

Asked how export-reliant Japan will cope with the imminent imposition of U.S. auto tariffs, Ishiba said his government will continue urging the United States to exempt its Asian ally.

He said he would fly to the United States to try to persuade President Donald Trump on the issue if "appropriate," though he emphasized that he expects the matter to be handled through discussions between the ministers in charge.

Ishiba's minority government has managed to secure the passage of the budget for fiscal 2025, but his Cabinet has been struggling with flagging support that has hit fresh lows in recent media polls.

His handing out of vouchers worth 100,000 yen each to 15 new Liberal Democratic Party members of the House of Representatives, or lower house, apparently hurt voter confidence, coming on top of a separate slush funds scandal at the ruling party.

"I have to admit I wasn't myself. I have to face it squarely and deeply reflect on it," Ishiba told reporters, noting that he was "concerned" about his image as a "stingy" person who does not socialize with people by holding dinner meetings.

He reiterated that the vouchers were meant to show his appreciation for the rookie members who were elected in the general election last October where the ruling camp lost their lower house majority.

"I will devote my heart and soul to securing the trust of each and every one of you" he said, in a message to the public.

The scandal poses a fresh challenge for Ishiba's ruling coalition as it heads toward the election for the House of Councillors, where the LDP and Komeito currently hold a majority.

Ishiba, who doubles as LDP president, stressed the need for "thorough" parliamentary debates over policy items to secure support from the opposition camp.

Asked about the possibility of holding the upper house and lower house elections at the same time, Ishiba said, "I'm not thinking about dissolving the lower house, holding simultaneous elections for both chambers, or reworking the ruling coalition."

The upper house election to replace half of the members must be held this summer, with voters expected to deliver their verdict on his steering of the government at a time when Trump's tariff threats have raised economic uncertainty.

The United States plans to enforce a 25 percent tariff on car imports without exceptions from Thursday.

Japanese officials have been in communication with the U.S. government seeking to get cars from Japan exempted from the move given the importance of the U.S. market to the country's automakers.

"Japan is the biggest investor in the United States. We will continue to strongly urge the United States to exempt Japan from the measure," Ishiba said.

To gauge the impact of the tariff hike on the Japanese economy, if imposed, the prime minister said, the government will collect information at around 1,000 consultation centers across the country and do "all it can" to meet the funding needs of affected companies.