Prime Minister Yoshiro Mori leaves today for an eight-day trip to four Southwest Asian countries, during which he is expected to call on India and Pakistan to sign an international treaty banning tests of nuclear weapons.

Mori also plans to press India and Pakistan to resume their peace talks, which have been suspended since last year, Foreign Ministry officials said. The trip will also take him to Bangladesh and Nepal.

Mori is due to meet with Pakistan's ruler, Gen. Pervez Musharraf, on Monday and with Indian Prime Minister Atal Behari Vajpayee on Wednesday, when he will urge them to sign the Comprehensive Test Ban Treaty.

India and Pakistan conducted tit-for-tat nuclear tests in May 1998, prompting Japan to impose economic sanctions on both countries.

If the two leaders promise to freeze nuclear tests, Mori will offer to partially lift sanctions and provide additional yen loans to ongoing projects, such as the construction of power plants, roads and subways, government sources said. The suspension of new grants, however, will remain in place until they sign the CTBT, they said.

Pakistan and India have fought three wars since gaining independence from Britain in 1947. World powers are trying to get the two nations to renounce their nuclear weapons, but both countries -- at loggerheads over Kashmir -- have refused, triggering concerns of another full-fledged conflict between them.

Kashmir is divided between Pakistan and India, which both claim the Himalayan region in its entirety.

India accuses Pakistan of fomenting a decade-long armed insurgency and refuses to hold talks with Islamabad until Pakistan stops supporting militants. Pakistan denies the charge, and calls the insurgency an indigenous movement.

An offer to partially lift the sanctions -- if actually made -- would indicate a softening of Japan's stance, which until now has made the signing of the CTBT a precondition for an end to the sanctions. It would also show Japan's willingness to mend relations with the two countries, especially with India.

"We cannot give fresh loans unless the two countries sign the CTBT," one government source said. "But we can give assistance to projects we offered to help with (before the sanctions) without changing that policy."

The CTBT stipulates that all 44 declared and potential nuclear nations must ratify the treaty for it to be put into effect. Of the 44, countries including China, Israel and the United States have yet to ratify the agreement, while India, Pakistan and North Korea have yet to sign it.

Both India and Pakistan say they have not obtained the national consensus needed to sign the treaty.

With India rising as an economic power, especially in the field of information technology, the Japanese government has come under growing pressure, both from political and business circles, to put an early end to its sanctions so as not to lose out on lucrative trade deals with India.

"If we do not lift the sanctions, we could be left out of the global trend," one Liberal Democratic Party legislator said, adding that the entire region is a huge potential market.

Members of the Japan-India Business Cooperation Committee, led by Chairman Nobuhiko Kawamoto, also called for an early end to the economic sanctions against India during their meeting with Mori on Wednesday.

In a bid to step up top-level dialogue between Japan and both nations, Mori will invite Vajpayee and Pakistani Foreign Minister Abdus Sattar to visit Japan, according to government sources.

In his meeting with Vajpayee, Mori will convey Tokyo's hope for exchanges of Cabinet ministers responsible for IT promotion and acceptance of more Indian IT experts into Japan, the sources said.

In a show of Japan's eagerness to promote cooperation in the IT field, Mori will visit Bangalore, India's version of Silicon Valley. He will also call for such cooperation in a speech to Indian business leaders.

In Pakistan, Mori will call for the nation to remain a democracy, emphasizing Musharraf's need to honor his pledge to hold national elections by October 2002, in line with the ruling handed down in March by Pakistan's Supreme Court.

Musharraf led an army coup last October that removed the government of Nawaz Sharif.

Japan's economic cooperation issues are also expected to top the agenda in Mori's talks with Bangladeshi Prime Minister Sheikh Hasina Wajed and Nepalese Prime Minister Girija Prasad Koirala. Japan is the biggest donor of aid to the two countries.

Mori is set to meet with the Bangladeshi leader today and with the Nepalese leader on Friday.