More than half of Chinese people think their country could go to war with Japan in the future, a new poll revealed Wednesday, after two years of intense diplomatic squabbles.

A survey conducted in both nations found that 53.4 percent of Chinese envisage a future conflict, with more than a fifth of those saying it would happen "within a few years", while 29 percent of Japanese view military confrontation as a possibility.

The findings come ahead of the second anniversary Thursday of Japan's nationalisation of disputed islands in the East China Sea that have formed the focus of tensions between the Asian giants.

Underlining the lingering row over the Tokyo-controlled Senkaku Islands, four Chinese coast guard vessels sailed into their territorial waters on Wednesday morning.

China regards them as its territory and calls them the Diaoyu Islands.

The survey was conducted by Japanese non-governmental organisation the Genron NPO and the China Daily, a Chinese state-run newspaper, in July and August.

It questioned 1,000 Japanese aged 18 or older and 1,539 Chinese of the same age range in five cities: Beijing, Shanghai, Chengdu, Shenyang and Xian.

In the annual opinion poll which started in 2005, 93.0 percent of Japanese respondents said their impression of China was "unfavourable," worsening from 90.1 percent last year and the highest level since the survey began.

The percentage of Chinese who have an unfavourable impression of Japan stood at 86.8 percent, an improvement on 92.8 percent last year.

"The most common reason for the unfavourable impression of China among the Japanese public was 'China's actions are incompatible with international rules' at 55.1 percent," Genron NPO and the China Daily said in a joint statement.

That was closely followed by "China's actions to secure resources, energy and food look selfish" at 52.8 percent.

The third most commonly-given reason was "criticism of Japan over historical issues" at 52.2 percent, while "continuous confrontation over the Senkaku islands" came fourth place at 50.4 percent, it said.

"On the other hand, 'The Diaoyu/Senkaku islands' (64.0 percent) and 'historical understanding' (59.6 percent) were the two prominent reasons for the unfavourable impression of Japan among the Chinese public," it said.

- Ties in decline -

Despite a huge trade relationship and their deeply interwoven economies, relations between Tokyo and Beijing have seen several periods of deterioration over recent decades.

But ties have been particularly bad since late 2012 when Japan nationalised the Senkakus, a move it says was just an administrative change, but which China says was a provocation.

Beijing regularly insists that Japan has not atoned enough for its imperialist past, and lambasts nationalist Prime Minister Shinzo Abe for an "incorrect" understanding of history and what it describes as his intention to remilitarise.

For its part, Tokyo accuses Beijing of dwelling on the past for domestic political reasons and says that in the seven decades since World War II it has apologised repeatedly and trodden a pacifist path.

In an editorial, the China Daily described the poll as "worrying", commenting that "these findings should be concerning" for leaders in both countries.

"There is a need for a meeting between the leaders of both countries to reverse the deteriorating relations," the paper said, but added: "the ball is in Japan's court."

"Abe needs to show Chinese leaders with his actual deeds that he is sincere about improving relations."

Abe has repeatedly said his door is open for dialogue and called for a summit with Chinese leader Xi Jinping, but has so far been rebuffed.