Western leaders gathering in Brussels have sought to build on a successful Ukrainian presidential election to push for a settlement between Moscow and Kiev.

At a two-day Brussels summit of the group of seven, which opened on Wednesday, Obama and European leaders warned the Kremlin of tougher economic sanctions unless Russia stopped facilitating violence in eastern Ukraine. "We stand ready to intensify targeted sanctions and to consider significant additional restrictive measures to impose further costs on Russia should events so require," the leaders said in a statement late on Wednesday.

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