(Combines stories, adds quotes)
MOSCOW, Sept 4 (Reuters) - Russia's foreign minister warned NATO not to offer Ukraine membership of the alliance as it gathered for a summit on Thursday and told the United States not to try to impose its will on the former Soviet republic.
Sergei Lavrov also urged Kiev and pro-Russian rebels fighting Ukrainian forces in eastern Ukraine to back peace moves outlined by President Vladimir Putin and avert what he said could be a large-scale crisis in the heart of Europe.
Putin unveiled the seven-point plan on Wednesday, the eve of a NATO summit at which the crisis in Ukraine will be discussed.
"It is precisely at such a moment when a chance has emerged to start solving specific problems between Kiev and the militias that some sections of the Kiev authorities make demands for Ukraine to drop its non-aligned status and start joining NATO," Lavrov said at talks with the Organization for Security and Cooperation in Europe, a rights and security group.
"It's a blatant attempt to derail all efforts aimed at initiating a dialogue on ensuring national reconciliation."
Moscow has long said it will regard NATO membership for Ukraine as a national security threat.
Underlining Moscow's concerns about U.S. influence on Kiev, Lavrov said: "Some of our Western partners, including unfortunately the most influential players - the United States - want victory for NATO and a situation where America dictates its will to everyone."
"This concept of exclusivity, which President (Barack) Obama has repeatedly declared, can lead to no good and has so far led to no good," he said.
Lavrov promised Russia would take "practical steps" to de-escalate the crisis in Ukraine and urged Kiev and rebel leaders to accept Putin's proposals for a ceasefire. (Reporting by Katya Golubkova, Writing by Timothy Heritage, editing by Elizabeth Piper)