The Japanese government is considering visits by Prime Minister Shinzo Abe to Britain and the Netherlands in early January before Switzerland and Russia later in the month.
During his visit from Jan 9 to Jan 11, he is expected to hold talks with British Prime Minister Theresa May to bolster cooperation in such fields as security and meet with Dutch Prime Minister Mark Rutte, the sources said.
Abe had initially planned to visit the two countries on the occasion of the Group of 20 summit in Argentina earlier this month but postponed it due to a tight parliamentary schedule at home.
He is expected to attend an annual meeting of the World Economic Forum in Switzerland that will run from Jan. 22 and then go to Russia for a summit with President Vladimir Putin, according to the sources.
At the international conference in the Swiss town of Davos, politicians, business leaders and others will discuss global issues.
In Moscow, the focus will be whether Abe and Putin can build on the recent momentum to advance peace treaty talks after they decided to task their foreign ministers to lead forthcoming negotiations during a meeting on the fringes of the G-20 summit on Saturday.
Foreign Minister Taro Kono and Takeo Mori, a senior Japanese deputy foreign minister who was tapped as a special representative for the talks, are also expected to accompany Abe, according to the sources.
Kono and his Russian counterpart Sergey Lavrov are expected to hold talks as early as this month to lay the groundwork for their leaders' meeting in late January.
In November, Abe and Putin agreed to step up peace talks based on a 1956 accord that mentions the handover of Shikotan and the Habomai islet group following the conclusion of a peace treaty.
Abe's fresh focus on the decades-old agreement with the former Soviet Union has led to the view that Abe will prioritize the islands first, a change from Tokyo's policy of securing all disputed islands off Hokkaido in northern Japan, including Etorofu and Kunashiri.
The unresolved spat over the islands, known in Japan as the Northern Territories and the Southern Kurils in Russia, has prevented the two nations from signing a postwar peace treaty.