NATO allies have "significant differences" with Russia over its demands for new security rules in Europe, but are ready to meet Kremlin envoys again, the alliance's chief Jens Stoltenberg said Wednesday.  

"There are significant differences between NATO allies and Russia on these issues, and the differences will not be easy to bridge," he said after talks with Russia at NATO headquarters in Brussels. "But it is a positive sign that all NATO allies and Russia sat down around the same table."

Stoltenberg warned that NATO might deploy additional troops to eastern allies should Russia use force against Ukraine. 

"If Russia once again uses force against Ukraine and further invades Ukraine, then we have to seriously look into the need to further increase our presence in the eastern part of the alliance," he told reporters after a meeting of the NATO-Russia Council, responding to a question. 

He warned of a "real risk for a new armed conflict in Europe," although he said NATO "will do what we can to prevent" any such scenario. 

Kremlin spokesperson Dmitry Peskov said earlier on Wednesday that Russia is not making ultimatums in its negotiations with the West but needs concrete answers regarding its security concerns. 

Russia last month sent a draft agreement to NATO and a draft treaty to the U.S. on security guarantees in Europe for the Western countries to consider. Moscow has asked Washington to prevent further eastward expansion of NATO and deny former Soviet republics accession to the alliance.  

Russia also demanded that the U.S. and NATO do not deploy offensive weapons in its neighboring countries. 

(With input from agencies)