Bucharest - Tougher sanctions must be imposed on Russia if it undermines crucial elections in Ukraine on Sunday, US Vice President Joe Biden said on Wednesday in Bucharest.
"If Russia undermines these elections on Sunday, we must remain resolute in imposing greater costs," Biden told reporters after meeting with Romanian president Traian Basescu.
"All countries should use their influence to promote a stable environment for Ukrainian citizens to cast their ballots freely."
Biden also praised the pro-Western government in Kiev for its "steps to engage Ukrainians, from all parts of that country, in the east and the south, on issues of constitutional reform".
And he reassured Nato member Romania of Washington's commitment to Article Five of the alliance's charter, which states that an attack on one member is an attack on all.
He said the pair had discussed "the ongoing and urgent efforts of the US and Nato to step up our military presence in Central and Eastern Europe in the air, on the sea and on the ground".