Japanese Prime Minister Shinzo Abe pledged Monday he will further expand his country's already improving ties with China but said Japan still needs to bolster its defense capability as far as space amid concern about Chinese military activity and uncertainty over North Korea's denuclearization.

In a policy speech to Parliament, Abe omitted references to South Korea, which he had routinely mentioned as Japan's most important neighbor, as Tokyo tries to distance itself amid escalating spats over history and alleged incidents between the two defense forces.

Abe said Japan-China relations have returned to "normal" since he visited Beijing in October and he now wants to further promote their cooperation in trade and other areas.

"Japan-China relations have fully returned to a normal orbit," Abe said. "I will elevate it to a next level by deepening exchanges in every area in all levels."

Apparently drawn closer amid shared trade friction with the U.S., the two Asian rivals have improved their ties since a low in 2012 during a dispute over east China Sea islands controlled by Japan but claimed by China.

Yet, Japan still needs to expand defense capability, especially in space and cyberspace, Abe said. Japan has repeatedly said China's growing military presence threatens regional security and its recent rapid advancement in space technology is an additional concern. Japanese officials have also said North Korea remains a missile and nuclear threat since it has not taken concrete steps except for a vague promise it made at the June summit with the U.S.

Japan, under pressure from President Donald Trump's demand for more American imports, is to start trade talks with Washington later this year. Japan has already increased purchases of expensive U.S. missile defense systems and other arms.

Maintaining good ties with China is one of most important diplomatic goals for Abe, but analysts said it may be affected by how things work out between the United States and China.

"Even if Prime Minister Abe wants to further improve Japan-China relations, it would be influenced by U.S.-China relations," said Harukata Takenaka, international politics professor at National Graduate Institute for Policy Studies. "It would be difficult for Japan to make a decision by itself."

Abe did not mention South Korea as the key U.S. allies and close economic partners are currently locked in disputes over military issues and wartime history. Japan's Defense Ministry is reportedly considering not participating in a multinational defense exercise planned in South Korea this spring.

Abe said he seeks to achieve unresolved postwar legacies during his leadership — settling island disputes and signing peace treaty with Russia and normalizing relations with North Korea, while cooperating with other countries toward achieving the North's nuclear and missile program abandonment.

The Soviet Union took the four southernmost Kuril Islands during the final days of World War II. Japan asserts territorial rights to the islands, which it calls the Northern Territories, and the dispute has kept the countries from signing a peace treaty. Abe has held dozens of meetings with Russian President Vladimir Putin in recent years in a bid to solve the dispute, and they agreed in November to accelerate negotiations based on a 1956 Soviet proposal to return two of the islands to Japan. Their talks this month in Moscow produced little progress.

The parliament's ordinary session lasts for 150 days until late June. Abe, who took office in December 2012 and is serving his third term, seeks to lead his party to win parliamentary elections in July and strengthen his grip on power until 2021 or possibly beyond.