The Philippines has barred two American senators from entering the country and threatened to impose visa restrictions on Americans if Washington imposes sanctions on Filipino officials involved in the imprisonment of an opposition leader, Reuters reported.

According to presidential spokersperson Salvador Panelo, Senators Richard Durbin and Patrick Leahy have no right to enter the country after the adoption of the US 2020 budget, which has provisions prohibiting officials involved in the imprisonment of Senator Leila de Lima from entering the US.

The latter is a critic of the war on drug trafficking, which was announced by President Rodrigo Duterte.

"We will not sit idly if they continue to interfere with our processes as a sovereign state," Salvador Panelo said.