Britain's foreign secretary will meet with foreign ministers from the Middle East and will discuss efforts to prevent wider regional escalation.
Jashua Bowles, repeatedly stabbed the unnamed woman, who was working at British intelligence agency GCHQ, in March near its base in Cheltenham in western England.
Waving the blue and white Israeli flag adorned with the Star of David, several participants wept as the names of hostages were read out to the crowd.
The Israeli police said in a statement on Tuesday that its cyber unit worked with British police to freeze a Barclays bank account linked to Hamas.
"There are not two sides to these events. There is no question of balance, I stand with Israel, we stand with Israel," Sunak said.
Being courteous costs nothing but can mean everything.
Sunak, who has long been a defender of the UK’s Jewish community and of the State of Israel, shook the lulav and etrog under the Board of Deputies of British Jews’ Sukkah.