The OECD, a key policy forum for advanced democracies, said that at the request of its 34 members it had "postponed activities related to the accession process" for the Russian Federation "for the time being".
OECD members had also agreed that the OECD "should respond positively to Ukraine's request to further strengthen existing OECD-Ukraine co-operation," the grouping said in a short statement.
The decision comes amid mounting international pressure on Russia over its incursion into Ukraine's Crimea peninsula, which has sparked a Cold War-style stand-off between Moscow and the West.
The OECD said that strengthening cooperation with Ukraine would enable the country "to take advantage of the OECD's expertise to address the public policy challenges it faces."
The statement said the OECD had informed the Russian Federation of the decision to postpone the accession process.