Japanese Prime Minister Shinzo Abe's trip to the United States, his first overseas visit since taking office, has been postponed until at least February, Japanese media reported on Monday.

Japan's Kyodo News Agency quoted government officials as saying that planning the visit has become difficult because of US President Barack Obama's busy schedule as he prepares for his inauguration ceremony on Jan 21.

But analysts said the delay shows Washington's hesitation about Abe's debut overseas trip since being re-elected.

"Abe's right-leaning attitude toward Japan's wartime history has drawn attention from the White House. The US is concerned that Abe's tough stance in handling relations with Asian neighbors may get out of control," said Yang Bojiang, an expert of Japanese studies at Chinese Academy of Social Sciences.

After taking office in December, Abe planned to visit the US as early as January for talks with Obama as his first overseas trip. Japanese Vice-Minister of Foreign Affairs Chikao Kawai is visiting the US this week to hold talks with his US counterpart — Deputy Secretary of State William Burns — and other officials to reschedule Abe's visit.

Meng Xiangqing, a professor of National Defense University, told media earlier that Abe has made a big effort to restore ties with the US as Japan sees strong backing from the US as important to counter China.

Kyodo News reported that in addition to visiting the US, Abe also intends to visit Russia in April or May to talk with Russian President Vladimir Putin about the two countries' dispute over the sovereignty of four disputed Pacific islands which are called Northern Territories in Japan and Southern Kuril islands in Russia. Russia seized the islands at the end of World War II. The two countries never signed a peace treaty after that war because of the dispute.

Former Japanese prime minister Yoshiro Mori will visit Russia in February as Abe's special envoy.

Abe has also dispatched and will send cabinet members to Asian countries that he says share basic values of democracy and fundamental human rights. Analysts say Japan's new cabinet is determined to pursue a "strong, yet pragmatic foreign policy", particularly in the Asia-Pacific region, to keep China's rapid rise in check.

Abe sent Fukushiro Nukaga, a Liberal Democratic Party lawmaker and former finance minister, to Seoul on Friday as the prime minister's special envoy.

Japanese Deputy Prime Minister Taro Aso just concluded a Myanmar visit last week, with Tokyo promising to provide more low-interest loans after writing off Naypyitaw's overdue debt by the end of January.

Japanese Foreign Minister Fumio Kishida will visit the Philippines, Singapore and Brunei as early as Wednesday to strengthen relations with the Association of Southeast Asian Nations. Kishida is expected to discuss with them maritime defense cooperation and the establishment of rules of navigation freedom.

"The so-called value-oriented diplomacy is only a set of talking points that Tokyo has adopted in its efforts to improve ties with neighboring countries, as most of them show more or less vigilance about China's rise," Yang said. "Appeals like political reforms and electoral systems could easily come up as a common language Japan could find with them."