Cambodian Prime Minister Hun Sen said Thursday he would "isolate and finish" exiled opposition figure Sam Rainsy, as the strongman continues to squeeze political challengers ahead of next year's national election.
Hun Sen -- who has ruled the kingdom for 37 years -- is running for office again and has backed his eldest son Hun Manet to succeed him.
Stepping up the rhetoric against his long-term foe, Hun Sen told reporters on Thursday he would "eliminate the extremist ideology of three-generation traitor" Rainsy to preserve the country's peace.
Hun Sen also said he would "isolate and finish" 73-year-old Rainsy, who had appealed on Sunday to the Cambodian people and army to liberate the country from the ruler's family.
Hun Sen warned any political party with links to the politician would face dissolution, and that people who offer him assistance could face repercussions.
His latest comments come a day after a Cambodian court sentenced Rainsy -- who has taken refuge in France, where he is a dual national -- to life imprisonment for allegedly attempting to cede territory to a foreign entity.
Rainsy is the co-founder of the banned Cambodia National Rescue Party (CNRP), which was dissolved ahead of 2018's widely criticised elections.
Rights groups say 70-year-old Hun Sen -- Asia's longest-serving leader -- has wound back democratic freedoms and used the courts to stifle opponents, jailing scores of opposition figures and activists.
And earlier this month a court in France cleared Rainsy in a defamation case brought by Hun Sen.
Cambodia will come under the international spotlight next month when it hosts an ASEAN summit in Phnom Penh.
At a meeting of ASEAN foreign ministers in August, US Secretary of State Antony Blinken expressed concerns about the kingdom's ailing democracy.