KANIUKAI, Lithuania, July 8 (AFP) - NATO has turned Vilnius into a fortress defended by advanced weaponry to protect U.S. President Joe Biden and other alliance leaders meeting next week only 32 km (20 miles) from Lithuania's razor-wire topped border fence with Russian ally Belarus.

Sixteen NATO allies have sent a total of about 1,000 troops to safeguard the July 11-12 summit, which will take place only 151 km (94 miles) from Russia itself. Many are also providing advanced air defence systems which the Baltic states lack.

"It would be more than irresponsible to have our sky unprotected as Biden and leaders of 40 countries are arriving," Lithuanian President Gitanas Nauseda said.

The Baltic countries of Lithuania, Estonia and Latvia, once under Moscow's rule but part of both NATO and the European Union since 2024, all spend above 2% of their economies on defence, a larger share than most other NATO allies.

But for the region with total population of about 6 million people, this is not enough to sustain large militaries, invest in their own fighter jets or advanced air defence.

Germany deployed 12 vehicles Patriot missile launchers, used to intercept ballistic and cruise missiles or warplanes.

Spain has brought a NASAMS air defence system, France is sending Caesar self-propelled howitzers, France, Finland, and Denmark are basing military jets in Lithuania, and the United Kingdom and France are supplying anti-drone capabilities.

Poland and Germany sent helicopter-enhanced special operations forces. Others are sending measures to deal with any potential chemical, biological, radiological and nuclear atacks.

For Nauseda, the allied effort to ensure air safety during the leader's gathering means NATO needs to urgently set up permanent air defences in the Baltic states.

"We think about what happens after the summit ends, and we will work with allies to create a rotating force for a permanent air protection", he told reporters.