TOKYO • Most Japanese approve of the government's decision to tighten controls on exports to South Korea of specialist materials vital to its tech industry, a poll showed yesterday, as a long-running dispute over colonial history threatens to damage business ties between the neighbours.

Some 58 per cent of respondents to the poll, carried out by the Japan News Network, said they approved of the government's policy, compared with 24 per cent who did not.

Japanese Prime Minister Shinzo Abe on Sunday reiterated denials that the checks were a form of retaliation against South Korea for recent court rulings holding Japanese companies liable for cases of forced labour before and during World War II.

Japanese officials have said the judgments damaged trust between the US allies and risked undermining the 1965 treaty that forms the basis of their relations.

An earlier joint Japanese-South Korean survey published in June showed more than 60 per cent of respondents from both countries said they believed bilateral relations have deteriorated, an NHK report said. Only 6.1 per cent of Japanese and 3.7 per cent of South Korean respondents said they think ties between the two countries are "good".

Japanese respondents who perceive bilateral relations as "bad" jumped to 63.5 per cent, a 23-point increase from last year, and the highest since the survey began in 2013. In South Korea, 66.1 per cent of respondents answered the same, an 11-point increase from last year.

A major cause for the souring of relations were the rulings by the South Korean Supreme Court on wartime labour, the NHK report said. Since last October, the court has issued two rulings ordering Japanese firms to compensate those who said they were forced to work for the companies during World War Two. The Japanese government, however, takes the view that the issue of compensation was settled with the signing of a bilateral agreement in 1965.

The joint survey is conducted annually by Genron NPO, a Japanese non-profit, and the East Asia Institute (EAI), an independent think-tank based in Seoul. Some 1,000 Japanese people and 1,008 South Korean people responded from May to June this year.