PHNOM PENH (Reuters) - Cambodian Prime Minister Hun Sen told his cabinet on Friday he had no fear of Western sanctions after some U.S. senators threatened to push for travel restrictions over his arrest of the main opposition leader, the government spokesman said.

Cambodia's Prime Minister Hun Sen attends a plenary session at the National Assembly of Cambodia in central Phnom Penh, October 16, 2017. REUTERS/Samrang Pring

Hun Sen’s critics accuse him of destroying democracy in Cambodia to ensure that he wins re-election next year to extend more than 32 years in power.

U.S. Senator Ted Cruz said he would push for a travel ban on top officials if opposition leader Kem Sokha is not freed by Nov. 9. Senators John McCain and Dick Durbin have also called for travel restrictions if the crackdown continues.

Hun Sen told a weekly cabinet meeting that sanctions by Western donors don’t worry him, the government spokesman said.

“Samdech said he doesn’t have wealth abroad and there is no necessity for him to step on U.S. soil,” Phay Siphan told Reuters, using Hun Sen’s official title.

Kem Sokha was arrested on Sept. 3 and charged with treason. He is accused of plotting to take power with the help of unspecified Americans - an accusation he denies.

The government has also asked the courts to dissolve Kem Sokha’s Cambodia National Rescue Party (CNRP) and Hun Sen has called on its members of parliament and other elected officials to defect to his Cambodian People’s Party (CPP).

Pro-government media said one parliamentarian and some local councillors had defected.

Kem Sokha’s daughter Monovithya Kem said that if he were not released and the pressure ended on the CNRP, it would mean that next year’s election would lack legitimacy.

“Hun Sen’s government cannot survive without that legitimacy,” she told Reuters. “Cambodia would become a pariah state if the government doesn’t reverse course soon.”

Western countries have called for the release of Kem Sokha and have intensified lobbying.

In an unusually direct statement from Japan, visiting vice minister for foreign affairs Iwao Horii called on Thursday for a free and fair election next year. Japan is Cambodia’s biggest aid donor after China.

“He expressed the expectation that Cambodia’s next national election will be conducted in a free and fair manner,” Hironori Suzuki, Counsellor at the Japanese Embassy, said in an email to Reuters. “He expected that the general election would be held in a way that the international community will welcome.”

Hun Sen has been increasingly isolated from Western donor pressure by his strong relationship with China, which has become by far the biggest giver of foreign aid as well as the biggest investor in Cambodia.