South Korea has warned the US of the potential damage from "undesirable" Japanese restrictions on exports of high-tech material to South Korea, as a trade row between the East Asian US allies intensifies.

As South Korea sought US help in the dispute, triggered by disagreement over the issue of compensation for South Koreans forced to work for Japanese firms during World War II, it also took steps to limit the damage to its companies.

South Korea's ruling party announced that up to 300 billion won ($255 million) would be included in a supplementary budget to cope with Japan's curbs on exports of three ­materials, crucial for advanced consumer electronics, by speeding localization of their supply.

The ruling Democratic Party said about one-third of the proposed budget would be for supporting South Korean materials and equipment makers to help them get their products to ­market.

The East Asian neighbors share a bitter history dating to Japan's colonization of the ­Korean Peninsula from 1910 to 1945.

Relations took a turn for the worse this week when Japan said it would tighten curbs on exports of the materials used to make chips and display panels because trust with South Korea had been broken over the forced labor dispute.

S&P Global Rating's Asia-Pacific chief economist Shaun Roache said the dispute was as unpredictable as the US-China trade war and was likely to ­affect South Korea's growth.

The Japanese restrictions will affect companies such as Samsung Electronics Co Ltd and SK Hynix Inc, which supply chips to companies such as Apple Inc.

South Korean Foreign ­Minister Kang Kyung-wha told US Secretary of State Mike Pompeo in a phone call late on Wednesday that Japan's restrictions may not only damage South Korean companies but could also disrupt the global supply chain and hurt US firms.

Kang "expressed concern that this is undesirable in terms of friendly relations between South Korea and Japan and trilateral cooperation among South Korea, the US and ­Japan," Kang's ministry said in a statement.

South Korea hoped Japan would withdraw the curbs and that the situation would not deteriorate further, it said.

Pompeo said he understood and they both agreed to strengthen communication between the three sides, it said.

However, analysts say the US is unlikely to become a ­mediator in the dispute.

South Korea and Japan also clashed at the World Trade Organization this week.

Kim Hyun-chong, deputy chief of South Korea's National Security Office, arrived in Washington on Wednesday and told reporters he would meet officials from the White House and Congress to discuss issues that included Japan's export curbs.