Copies of a booklet from the Central Commission for Discipline Inspection, the ruling Communist Party's anti-graft watchdog, is seen on a table during their news conference in Beijing, China, January 15, 2016. REUTERS/Kim Kyung-Hoon

SHANGHAI (Reuters) - China needs to “narrow its differences” with Western countries where corrupt officials have fled and seek their support, the country’s top graft watchdog said, as Beijing seeks to address worries about rule of law and transparency in corruption probes.

China has sought to boost international cooperation in its “Fox Hunt” campaign to track down officials and business executives suspected of corruption who have fled abroad.

But Western nations have been reluctant to sign extradition treaties with China, where mistreatment of criminal suspects remains a problem, and courts are not independent of the ruling Communist Party. They say China has not provided sufficient proof of suspects’ crimes.

The Central Commission for Discipline Inspection noted in an online statement late on Sunday that China’s extradition treaties and criminal judicial assistance programs were mostly with developing countries, but corrupt officials tended to flee to developed Western countries.

“We must strengthen our coordination and cooperation with the countries where corrupt elements flee, clearly express our ideas, narrow differences, seek support, and reject the provision of havens for corrupt elements,” it said.

Chinese President Xi Jinping has waged a years-long campaign against graft that has felled hundreds of officials at all levels of government, including many of his top political rivals.

Earlier this month, the CCDI, which is an arm of the ruling Communist Party, condemned “some people” who protect corrupt officials in the name of human rights, but did not name the targets of its ire.