He joined foreign ministers from Canada, Sweden, Ukraine and Afghanistan, who all lost citizens in the crash, in lighting a five wick candle before observing a moment of silence.
Behind the ministers a plaque on the wall listed the names of the crash victims.
It comes as Iran makes repeated threats, this time to European troops in the Middle East. Defence Secretary Ben Wallace said the UK takes the threats seriously, adding they do not escalate the situation.
Tehran said troops would be at greater risk, should they join a US-led campaign against it. Britain, France and Germany have spent months trying to protect a nuclear deal, which Washington unilaterally abandoned in 2018 amid rising tensions.
European countries have troops in Afghanistan, Iraq and elsewhere in the Middle East, where they mainly operate alongside much larger U.S. deployments. Iran is allied with powerful armed groups in Iraq, Syria, Lebanon and Yemen.
Foreign minister to join meeting responding to Iran crisis
Later today, Mr Raab will join his ministerial counterparts for a meeting of the International Coordination and Response Group.
Attending the meeting will be Canada’s minister of foreign affairs Francois-Philippe Champagne, Ann Linde, Sweden’s minister of foreign affairs, Vadym Prystaiko, Ukraine’s minister of foreign affairs and Idrees Zaman, acting foreign minister for Afghanistan.
Stef Blok, minister of foreign affairs for the Netherlands, who observed the candle lighting ceremony, is also due to be at the meeting.
In a tweet sent before the memorial event, Mr Prystaiko said he had met Mr Raab and appreciated “his words about firm and unquestionable support” for Ukraine.
He said the two men had agreed to work together over investigations into the plane crash and other issues, including defending Ukraine’s sovereignty.
All 176 people, including four British nationals, on board the Ukrainian International Airlines flight from Tehran to Kyiv were killed when the plane came down moments after take-off last week.
The majority of the plane crash victims were Iranians or Iranian-Canadians.
British citizens Sam Zokaei, Saeed Tahmasebi Khademasadi and Mohammad Reza Kadkhoda Zadeh were identified as among the dead.
After initially denying claims it was responsible, Iran has since admitted unintentionally shooting down the aircraft.
Prime Minister Boris Johnson has called for a “comprehensive, transparent and independent international investigation” into the crash.
In a previous statement he said the Government will do everything it can to support the families of the British victims and ensure they get “the answers and closure they deserve”.