TOKYO (Kyodo) -- Japanese Prime Minister Shigeru Ishiba on Monday failed to secure a tariff exemption during a telephone call with U.S. President Donald Trump, but the two leaders agreed the issue should be further discussed by their ministers.

Ishiba said he conveyed Japan's serious concern that the "unilateral" imposition of tariffs on Japanese products would hurt investment by Japanese firms, adding that the two nations should pursue broader, mutually beneficial cooperation instead of tariffs.

Trump, who has announced a 24 percent "reciprocal" tariff on Japanese products effective Wednesday, said on his social media that Japan will send "a top team to negotiate" over the issue. He said the United States has been treated "very poorly" on trade in an apparent bid to justify his tariff salvo.

Along with a 25 percent tariff on U.S.-bound Japanese cars already in place, Trump's onslaught of higher duties threatens to deal a debilitating blow to the export-reliant Japanese economy.

Ishiba has taken the view that Japan is facing a "national crisis" and vowed to do whatever his government can to protect the economy, including continuing to urge Trump to rethink the measures.

"I told him that we should explore how we can cooperate broadly in a way that can benefit both nations, including via more investment rather than unilateral tariffs," Ishiba said.

"Both sides will appoint ministers in charge" to continue discussions, he told reporters.

The phone talks came just days after Ishiba said he would seek a call before considering in-person negotiations with Trump to make his case that Japan, a close U.S. ally, should be exempt from tariffs.

Two leaders agreed to continue talking in a "candid and constructive" manner, Ishiba said, reiterating his wish to sit down with Trump "at the appropriate time" in the United States. He declined to specify when.

In parliament earlier in the day, Ishiba ruled out taking the path of a retaliatory tariff, saying that Japan "won't engage in tit-for-tat."

Instead, Japan should make clear to Trump that it has contributed to the U.S. economy by creating jobs and making investments, Ishiba said, adding that his country has not done anything "unfair."

The remark came as Trump argues that the United States has been "ripped off" by its trading partners, as evidenced by massive trade deficits.

"We are considering all options to determine what would be the most effective way" to address the tariff issue, Ishiba told a session of a House of Councillors committee.

Ishiba said that if he has a chance to visit the United States, he would not simply seek exemption from reciprocal tariffs but present a "package" to the Trump administration showing what the close U.S. ally can offer.

Japan negotiated a trade deal with the United States during Trump's first term as president.

Under the pact that entered into force in 2020, Japan lowered its tariffs on farm produce and beef from the United States while it failed to see a cut in U.S. tariffs on Japanese cars and auto parts.

Trump's recent tariff announcements have sent shock waves through global financial markets, sending Japanese stocks tumbling and lifting the Japanese yen against the U.S. dollar.

Chief Cabinet Secretary Yoshimasa Hayashi said at a regular press conference that the Japanese government will "continue to closely monitor economic and financial market developments both at home and abroad with a sense of urgency" and vowed to "do all it can" in terms of economic and fiscal policy management.

Even as Finance Minister Katsunobu Kato called on investors to stay "calm," Japan's Nikkei stock index suffered its third-largest point drop on record on Monday, ending 7.83 percent lower from Friday's close.

Ishiba instructed Kato to closely monitor financial markets and respond appropriately during a rare Sunday gathering of Cabinet members that involved Hayashi and economic revitalization minister Ryosei Akazawa.

So far, Trump appears unfazed by the global stock market rout, telling reporters aboard Air Force One on Sunday, "I don't want anything to go down, but sometimes you have to take medicine to fix something."

Since returning to the White House in January, Trump has introduced various duties, including an additional 25 percent tariff on cars produced outside the United States and 25 percent levies on all steel and aluminum imports.