The Philippines on Friday announced it had banned two U.S. lawmakers from visiting the country, and threatened to restrict entry for American citizens.
The move is in retaliation for an American threat to block travel to Philippine officials involved with the jailing of a government critic.
Democratic Senators Dick Durbin of Illinois and Patrick Leahy of Vermont introduced a measure into a 2020 budget deal sanctioning anyone involved in arrest and incarceration of Philippine Senator Leila de Lima.
(SOUNDBITE) (Filipino) PHILIPPINE SENATOR, LEILA DE LIMA, SAYING (FEBRUARY 23, 2017): "Like I said before, I have no plans to run away from these cases.
I have no plans to hide because I will face these cases." De Lima was charged with drug offenses in early 2017 after she led an investigation into mass killings during President Rodrigo Duterte's bloody war on drugs.
(SOUNDBITE) (Filipino) PHILIPPINE SENATOR, LEILA DE LIMA, SAYING (FEBRUARY 24, 2017): "The truth will be out in the right time.
If they think they can silence me, if they think I can no longer fight for what I'm fighting for, especially finding the truth behind the daily killings, the other issues, the pressures and tyranny under Duterte's regime, then it is my honour to get arrested because of what I'm fighting for.
The measure by Leahy and Durbin was part of a budget deal passed by Congress and signed by President Donald Trump.
And it outraged Manila.
A presidential spokesperson on Friday said "We will not sit idly if they continue to interfere with our processes as a sovereign state." President Donald Trump has in the past sided with foreign countries against elected Democratic U.S. lawmakers.
Over the summer he supported Israel's decision to block travel to two Democratic members of the House of Representatives.
The U.S. embassy in Manila did not immediately respond to a request for comment.