Russia's foreign minister is warning NATO not to extend an invitation for membership to Ukraine. Sergei Lavrov's remarks came on the eve of a Thursday NATO summit in Wales, where the fighting between Ukrainian forces and pro-Russian separatists will likely be discussed.

According to Lavrov, Moscow would regard NATO membership for Ukraine as a national security threat. He said the possibility of Ukraine dropping its non-aligned status could not come at a worse time, as President Vladimir Putin has presented a seven-point ceasefire proposal.

Speaking before the Organization for Security and Cooperation in Europe Wednesday, Lavrov said, ""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. It's a blatant attempt to derail all efforts aimed at initiating a dialogue on ensuring national reconciliation."

Lavrov fears a Ukrainian alliance with NATO would not only stifle talks with Kiev, but could also lead to increased U.S. influence in the region, something Moscow has long dreaded.

"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," he said. "This concept of exclusivity, which President Obama has repeatedly declared, can lead to no good and has so far led to no good."

Lavrov said Russia will take "practical steps" of its own to de-escalate the situation in Ukraine, and is urging Ukrainian officials and rebel leaders to accept Putin's proposals.

Meanwhile, President Obama is expected to ask NATO leaders to increase military spending in order to address threats from a resurgent Russia and ISIS militants in Iraq.