Prime Minister Shinzo Abe on Thursday pledged to lift oft-strained relations with China to a "new dimension," hours after he arrived in Beijing for the first official visit to the neighboring power by a Japanese political leader in nearly seven years.

"Today, Japan and China are playing an essential role in economic growth, not only in Asia but in the world," Abe said in a speech at a reception to celebrate the 40th anniversary of a peace and friendship treaty taking effect between the two countries.

"As problems that cannot be resolved by one country alone have risen, the time has come for Japan and China to jointly contribute to world peace and prosperity," Abe said, adding he is eager to forge a "new dimension" of the two nations' cooperation in a "new era."

His comments come at a time when bilateral ties, often frayed over territorial issues, have been markedly improving, while tensions between Beijing and Washington have been escalating over trade as well as Taiwan and the South China Sea."

Until late last year, Sino-Japanese relations had remained strained due to a long-running sovereignty dispute over a group of uninhabited islets in the East China Sea that flared up in 2012.

Abe also told reporters before leaving Tokyo that he would exchange views with President Xi Jinping and Premier Li Keqiang on bilateral efforts to bolster a free and fair trading system and make the East China Sea a "sea of peace, cooperation and friendship."

At his planned meetings with the Chinese leaders, however, Abe is expected to effectively shelve the issue of territorial sovereignty over the Senkaku Islands to emphasize friendly ties.

The group of islets, called Diaoyu in China, are controlled by Tokyo but claimed by Beijing.

Li said in a speech at the same reception, "Uncertainties over the global economy and politics have been growing. China-Japan relations have returned to a normal track, which would provide great benefits to the region and the world."

In May, Li traveled to Japan for the first time since he became China's head of government in 2013. It was the first official visit by a Chinese premier since 2011. Abe and Li held informal talks before the reception on Thursday.

Abe is scheduled to stay in Beijing for three days through Saturday.

At Tiananmen Square in the heart of China's capital, Japanese national flags have been placed, a symbolic gesture bolstering expectations of improved relations. On Friday, Abe is set to hold separate meetings with Li again and Xi.

It is the first visit by a Japanese prime minister primarily to hold official talks with Chinese leaders since late 2011, although Abe, who returned to power in late 2012, attended international meetings in China. Abe's immediate predecessor Yoshihiko Noda visited China in December 2011."

Abe is accompanied on the trip by Japanese Foreign Minister Taro Kono, Economy, Trade and Industry Minister Hiroshige Seko and a large number of business leaders.

As part of efforts to promote high-level reciprocal visits, Abe wants to invite Xi to visit Japan in June next year, when the country hosts the Group of 20 summit in Osaka.

With Li, Abe is likely to agree on the need to promote the interconnectivity of the region's economies amid a deepening trade war between China and the United States.

The two premiers are expected to agree on an expanded currency swap line worth around 3 trillion yen ($26.6 billion) to be better prepared for a financial crisis, Japanese government sources said.

Abe also plans to tell Li that Japan will discontinue its 40-year official development assistance to China, but instead propose setting up a new dialogue for Tokyo and Beijing to talk about cooperation to help infrastructure building in developing countries, according to the sources.

In Thursday's speech, Abe said Tokyo's ODA to Beijing has "completed its historical mission," now that China has become the world's second largest.

Li, meanwhile, asked Japan to cooperate in China's "One Belt, One Road" cross-border infrastructure initiative to invigorate investment in what he calls "third nations."

China has sought to expand its infrastructure networks in Asia, the Middle East, Europe and Africa to achieve its goal of connecting countries along the ancient Silk Road more closely, but fears remain in Japan over Beijing's transparency in its projects and financing.

On the security front, Abe and the Chinese leaders are likely to confirm cooperation to work toward the denuclearization of North Korea.

Japan and China will also sign an agreement to facilitate cooperation over search and rescue operations in the event of accidents in waters off the two countries, the sources said.

For years, Tokyo and Beijing have been mired in a territorial row over the Senkaku Islands. The dispute intensified after the Japanese government of then Prime Minister Noda brought the Senkakus under state control in September 2012.

Noda's move sparked anti-Japanese protests across China. At that time, many Chinese people burned Japanese national flags in opposition to Japan's nationalization of the uninhabited islands.

Japan and China on Tuesday marked the 40th anniversary of the Treaty of Peace and Friendship, in which the two neighbors have promised to pursue the development of ever-lasting peaceful and friendly ties.

(Satoshi Iizuka in Tokyo contributed to this story.)