The ministers from Afghanistan, Britain, Canada, Sweden, and Ukraine are expected to put fresh pressure on Iran to give a full accounting of what happened to the Ukraine International Airlines (UIA) Boeing 737-800.
The plane had just taken off from Tehran en route to Kyiv on January 8 when it was shot down by Iran’s air defenses, killing all 176 people on board.
Iran says the plane was brought down by error, hours after Iranian ballistic missiles targeted two bases housing U.S. forces in Iraq.
The victims of the crash included Iranian and Canadian nationals, with smaller numbers of Ukrainians, Afghans, Swedes, Britons, and Germans.
Countries have called for those responsible for the tragedy to be held accountable.
The possibility of taking legal action and the issue of compensation to families of the victims would also be discussed at the London meeting, according to Ukrainian Foreign Minister Vadym Prystayko.
Ahead of the talks, the ministers from the five countries lit candles at the Canadian High Commission to honor the dead.
The plane disaster has angered many Iranians, leading to protests against the clerical establishment.
On January 16, mourners shouted “death to the dictator” as they buried victims of the plane disaster in the western Iranian city of Sanandaj, videos posted online showed.
They referred to Iranian Supreme Leader Ayatollah Ali Khamenei.