Lavrov calls Nemtsov murder 'heinous crime'; urges moves by Ukraine
He addressed the Geneva forum shortly before U.S. Secretary of State John Kerry and after the foreign ministers of Croatia and Slovakia voiced concern at the killing in Moscow on Friday.
Lavrov also called on Ukraine to distance itself from what he called "extremists" in the east and pursue a course towards peace. He said "tangible progress" had been achieved in implementing measures agreed in Minsk this month and that the ceasefire was being "consolidated".
But he urged the Kiev government to lift what he called a 'de facto blockade' of the Donbass region, restore economic ties, pay social benefits, banking services and freedom of movement from Donbass to other parts of country.
(Reporting by Stephanie Nebehay; Editing by Janet Lawrence)