NATO will deploy a large military force on its border with Russia, the alliance's chief told The Telegraph.

Jens Stoltenberg said that the military "reset" aims to defend against an invasion by Russia. The alliance currently has a small "tripwire" presence along the border with Russia.

NATO will deploy a permanent full-scale military force on its border with Russia to defend its territory against a future Russian invasion, the alliance's chief said during an interview with The Telegraph.

NATO Secretary-General Jens Stoltenberg told the newspaper that the alliance was "in the midst of a very fundamental transformation" that will reflect "the long-term consequences" of Russian President Vladimir Putin's actions.

"What we see now is a new reality, a new normal for European security," Stoltenberg said, per The Telegraph. "Therefore, we have now asked our military commanders to provide options for what we call a reset, a longer-term adaptation of NATO."

The alliance currently has a small "tripwire" presence to the west of Russia. NATO troop numbers have increased tenfold to 40,000 since the invasion of Ukraine, The Daily Mail reported.

The "reset" will involve deploying sufficient forces to repel any offensive on NATO nations by Russian troops, per The Telegraph. NATO members bordering Russia include Estonia and Latvia.

NATO military commanders are currently discussing and developing their options, the newspaper said.

Stoltenberg will raise the issue of a bolstered military presence at a NATO summit in Madrid in June, according to Reuters.

NATO has had to tread carefully during the war in Ukraine, working out how best to support the war-torn nation while avoiding an escalation and getting drawn into the conflict.

Members of the alliance agreed on Friday to offer more military support to Ukraine.

Slovakia Prime Minister Eduard Heger confirmed on Friday that it had sent its S-300 air defense system to Ukraine, becoming the first NATO country to answer the calls by President Volodymyr Zelenskyy to supply powerful missile weaponry.

The S-300 is a Soviet-era long-range surface-to-air missile system that can shoot down cruise missiles and aircraft and has a range ofup to 90 miles.

The Czech Republic became the first NATO country to send tanks to Ukraine earlier this week, as a Czech defense source told Reuters.