Malacanang on Sunday branded as "nonsense" the call of a United States senator to “unconditionally” release detained opposition Senator Leila De Lima.

“We don’t respond to nonsense,” Presidential spokesperson Salvador Panelo told reporters in a text message when asked to comment on the statement of American Senator Marco Rubio, calling for the freedom of De Lima, who already spent two years in detention due to her alleged involvement in illegal drugs.

“Philippine Senator Leila de Lima, a critic of extrajudicial killings under Duterte's so-called 'war on drugs', has spent the last two years in prison on bogus charges,” Rubio said on his Twitter.

“I call on the Philippine government to unconditionally release her #FreeLeilaNow #ExpressionNOTOppression,” he added.

A Republican senator, Rubio is one of the five US senators who earlier filed a resolution in the US Senate condemning De Lima's continued detention.

De Lima, who is one of President Rodrigo Duterte’s staunchest critics, has been detained since February 2017 for her alleged involvement in the illegal drugs trade at the New Bilbid Prison when she was still the Justice Secretary in the previous administration.

The former Justice Secretary-turned senator denied the accusation. She is now detained inside the Philippine National Police Custodial Center in Camp Crame. Ella Dionisio/DMS