TOKYO (Kyodo) -- Prime Minister Shigeru Ishiba expressed concern over the potential negative impact of U.S. tariffs on Japanese companies operating in Southeast Asia, during phone talks with his Singaporean counterpart on Monday, the government said.

Ishiba and Singaporean Prime Minister Lawrence Wong exchanged views on economic issues, such as how the tariffs imposed by U.S. President Donald Trump and China's retaliatory measures will affect the global economy and the multilateral free trade system.

Tokyo has recognized the importance of maintaining close communication with Southeast Asia to tackle "such challenging circumstances," Ishiba said, adding Japan is eager to continue developing relations with Singapore, according to the government.

Earlier this month, Trump announced country-specific tariffs, including high-rate levies on some ASEAN nations, such as 49 percent on Cambodia and 46 percent on Vietnam, although he later announced a 90-day pause for most of them.

Trump, meanwhile, has raised tariffs on China, whose economic presence is particularly strong among members of the Association of Southeast Asian Nations, prompting Beijing to take tit-for-tat measures against Washington.