China sent its ships into territorial waters around disputed islands Friday, in the first incursion since Japan elected a new government.

The move is a setback to hopes in Tokyo that Beijing might use the poll as a chance for a fresh start after months of bitter wrangling and rhetoric over an issue that neither side is prepared to budge on.

Japan's coastguard said three surveillance vessels moved inside the 12-nautical mile band around the Tokyo-controlled Senkakus, which Beijing calls the Diaoyus, with a fisheries patrol ship logged in adjacent waters.

At nightfall they remained in the area, it said.

China has sent ships into the islands' waters 19 times since Tokyo nationalised the chain in September, according to a coastguard tally, with analysts saying Beijing intends to prove it can come and go as it pleases.

The ante was upped last week when a Chinese plane overflew the area, in what Japan said was the first time Beijing had breached its airspace since at least 1958. Tokyo scrambled fighter jets in response.

But the well-equipped coastguard says State Oceanic Administration vessels had stayed outside territorial waters since Sunday's election, in which the hawkish Shinzo Abe swept to power, vowing a tough line on Beijing.

In one of his first broadcast interviews after the win he said there was no room for compromise in the row and put the onus for improved relations on Beijing.

"Japan and China need to share the recognition that having good relations is in the national interests of both countries," he said. "China lacks this recognition a little bit. I want them to think anew about mutually beneficial strategic relations."

Friday's return to the pre-election pattern is a sign Beijing "doesn't want to compromise and wants to keep the pressure" up, said Robert Dujarric, director of Temple University Japan's Institute of Contemporary Asian Studies.

"It shows that Beijing wants to continue the confrontation. A new prime minister always opens up the possibility of 'hitting the restart button' but clearly Beijing is not interested in improving relations."

Following the latest incursion, Chinese foreign ministry spokeswoman Hua Chunying said: "Official Chinese vessels have always maintained routine rights protection patrols in the waters of the Diaoyu islands."

Abe has pushed an agenda that includes upgrading the country's "Self Defence Forces" to make them a full-scale military, and has spoken of wanting to revise Japan's pacifist constitution.

But analysts have said at least some of this could be posturing.

They point to the pragmatism of his 2006-2007 tenure as prime minister, when his opinions on controversial issues that could aggravate China were ambiguous or were left unsaid.

As premier he stayed away from Yasukuni Shrine, which honours Japan's war dead, including war criminals, and is a running sore in Tokyo's relations with its neighbours.

Abe also made China his first foreign destination.

Following his victory on Sunday, he said he would make rebuilding Japan's alliance with Washington his top foreign policy goal and said it would be the first place he visits after assuming office.

Despite warm words about the importance of economic ties with Beijing -- China is Japan's biggest trading partner -- Abe stressed the need to build relations with other countries, such as India and Australia.