European Parliament President Roberta Metsola has reiterated her call for justice for murdered journalist Daphne Caruana Galizia, saying that those responsible must continue to face the consequences of their actions.

In a message addressed to Caruana Galizia, Metsola said the recent days surrounding the trial had been particularly difficult for the journalist's family and loved ones, who have been forced to relive the events surrounding her assassination.

Caruana Galizia was killed by a car bomb outside her home in Bidnija in October 2017. Metsola said the promise made after her murder - to ensure that those who ordered and carried out the assassination, as well as those who sought to cover it up, were held accountable - remained in place.

"That promise holds today," Metsola said, insisting that there would be no giving up or giving in in the pursuit of justice.

She said those responsible should not expect public fatigue to end the search for accountability, particularly in relation to the corruption Caruana Galizia had spent years exposing.

Metsola also said that, despite attempts over the past nine years to silence the journalist, her voice had not been buried.

"Nearly a decade after they stopped you writing, your pen is still mightier than all their swords combined," she said.