British Foreign Secretary Philip Hammond claimed the tragedy "happened in the first place because of Russian support for the rebels" and that foreign ministers meeting in Brussels on Tuesday had to address that issue.
An EU leaders' summit on Wednesday recommended that the 28-member bloc extend its sanctions against Russian and Ukrainian figures for their role in the crisis but the downing of flight MH17 had changed the situation completely, Hammond said.
"The world has changed since then ... and (now) we have to go further," he said as he arrived for the meeting.
An arms embargo "is one of the things that we will have to look at," he said, adding that the EU had to send "a very clear message" to Moscow.
Several other EU foreign ministers made the same point, with Lithuania's Linas Linkevicius arguing that the rebels in eastern Ukraine should be treated as terrorists.
"We are talking about a terrorist act," Linkevicius said.
British Prime Minister David Cameron on Monday had called on the EU to adopt tougher "Phase 3" sanctions and to halt all arms sales to Russia, citing specifically a French contract for two warships worth 1.2 billion euros.
French Foreign Minister Laurent Fabius made no comment on the issue when he arrived for Tuesday's talks.
"To deliver arms to Russia is a position difficult to defend," Swedish Foreign Minister Carl Bildt commented.
Over the weekend, the leaders of France, Britain and Germany warned Russia it could face further EU sanctions if it did not pressure the rebels to allow unrestricted access to the crash site of flight MH17.
Since then, the rebels have handed over some 200 bodies and the flight recorders to investigators.
Brussels has so far hit 72 Ukraine and Russian figures with travel bans and asset freezes but there is reluctance to go further given some member states' close economic ties with Russia.
The sanctions are referred to as Phase 2 measures and preparatory work has been done on next-level Phase 3 steps, which would target economic sectors and inflict much more pain.
Wednesday's EU summit agreed to extend the scope of the Phase 2 sanctions, with a new list of targets to be ready by the end of the month.
However, Moscow has severely criticized the US and EU for politicizing the tragic incident and for pointing the blame finger at the Kremlin without even waiting for the results of an investigation. No official documents have been released over the main reason and agent of such tragic airplane crash yet.
NJF/NJF