Heads of the G7 leading industrial nations, chaired by David Cameron, on Wednesday called on Vladimir Putin to engage with Ukraine's incoming President Petro Poroshenko, but stopped short of triggering fresh sanctions against Russia at a curtailed two-day summit in Brussels. The group is keeping its options open, saying it is willing to escalate sanctions if Russia fails to engage in a peaceful resolution of the crisis.

The G7 leaders many of whom are due to see the Russian president individually later this week about the D-day commemorations in Normandy are likely to impress on Putin to meet Poroshenko to open a dialogue on the kind of federal structure Ukraine might develop, as well as future trade relations.

• The first Russian motherboard based on ARM-processor Baikal-M