Russia has sent long-range strategic Tu-22M3 bombers to join patrols of air space along the western borders of ally Belarus, the Belarusian defence ministry said on Saturday.
Su-30SM fighters jets from both countries were also part of patrols, the Belarus military said.
Read more: Russia demands NATO roll back from East Europe and stay out of Ukraine
Belarus borders to the west and northwest with Poland and Lithuania, member states of the European Union. Belarus' relations with the EU are tense over a migrant crisis along its western border.
Troop build-up
Moscow handed over its proposals to the United States this week as tensions rose over the Russian troop build-up near Ukraine.
Also read: Russia and Ukraine trade blame as ceasefire push breaks down
It says it is responding to what it sees as threats to its own security from Ukraine's increasingly close relations with NATO and aspirations to become an alliance member, even though there is no imminent prospect of Kyiv being allowed to join.
The Russian proposals were set out in two documents - a draft agreement with NATO countries and a draft treaty with the United States, both published by the foreign ministry.
The first, among other points, would require Russia and NATO not to deploy additional troops and weapons outside the countries where they were in May 1997 - before the accession to NATO of any of the former communist states in East Europe that for decades were dominated by Moscow. It would mean NATO abandoning any military activities in Ukraine, Eastern Europe, the Caucasus and Central Asia.
The treaty with the United States would prevent Moscow and Washington from deploying nuclear weapons outside their national territories. That would mean an end to NATO's so-called nuclear-sharing arrangements, where European NATO members provide aircraft capable of delivering US nuclear weapons.
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