Sharjah24 - Reuters: President Vladimir Putin warned the West on Monday that Russia would respond if NATO began to bolster the military infrastructure of Sweden and Finland which have both decided to join the U.S. military alliance after the invasion of Ukraine.

Putin, Russia's paramount leader since the last day of 1999, has repeatedly cited the post-Soviet enlargement of the NATO alliance eastwards towards Russia's borders as a reason for the conflict of Ukraine.

Speaking to the leaders of a Russian-dominated military alliance of former Soviet states, Putin said the enlargement of NATO was being used by the United States in an "aggressive" way to aggravate an already difficult global security situation.

Russia, Putin said, had no problem with Finland or Sweden, so there was no direct threat from NATO enlargement which included those countries.

"But the expansion of military infrastructure into this territory would certainly provoke our response," Putin told the leaders of the Collective Security Treaty Organization, which includes Belarus, Armenia, Kazakhstan, Kyrgyzstan and Tajikistan.