US lawmakers from both parties, friends of murdered journalist Jamal Khashoggi and press freedom groups on Thursday marked 100 days since the Saudi dissident's assassination.
Featuring a portrait of Mr Khashoggi against a back drop of American flags, the ceremony began with a moment of silence.
"The murder of Khashoggi is an atrocity and an affront to humanity," said Speaker of the House Nancy Pelosi during the event in Washington.
Mr Khashoggi, a Washington Post contributor who lived in the US, was killed in October at the Saudi consulate in Istanbul, where he had gone to pick up paperwork needed for his upcoming marriage to his Turkish fiancee.
Over three months later, his body's whereabouts remain unknown. Turkish and US officials accuse Crown Prince Mohammed bin Salman of orchestrating the killing -- an allegation Saudi authorities categorically refute.
In Washington, US President Donald Trump's response to Riyadh -- a key trade partner -- provoked outrage among lawmakers across the political spectrum.
"If we decide that commercial interest should override the statements that we make and the actions that we take, then we must admit that we have lost all moral authority to talk about any atrocities anywhere, any time," Ms Pelosi added.
The newspaper's CEO Fred Ryan said Mr Khashoggi's death had "touched his Washington Post colleagues deeply."
"Yet this story is not just about the murder of one innocent journalist," he added.
"Jamal's killing is part of an escalating attack against press freedom that is being waged by tyrants around the world."
Meanwhile Margaux Ewen, North America director for Reporters without Borders, warned that "journalists, bloggers, and media workers are under threat" every day.
"Together, let's make sure the sacrifices of those like Jamal who have paid the ultimate price have not been in vain," she said.
Amnesty International had earlier on Thursday appealed for a United Nations-led investigation into Mr Khashoggi's death.