Nato Secretary General Jens Stoltenberg speaks during a media conference at a NATO summit in Brussels. Photo / AP
Nato leaders have pledged to respond collectively to attacks in space, meaning that an attack on one member will be considered an attack on all.
Article 5 of the alliance's founding treaty, mandating collective military action, has previously only applied to more traditional military attacks on land, sea, or in the air.
In December 2019 space was declared by Nato as the alliance's "fifth domain".
Around 2000 satellites orbit the earth, of which more than half are operated by Nato countries. Military commanders rely on some of them to navigate, communicate, share intelligence and detect missile launches, while civilians use them for everything from mobile phone and banking services to weather forecasts.
In a statement released after the summit in Brussels, the leaders said they "consider that attacks to, from, or within space" could be a challenge to Nato that threatens "national and Euro-Atlantic prosperity, security, and stability, and could be as harmful to modern societies as a conventional attack".
"Such attacks could lead to the invocation of Article 5. A decision as to when such attacks would lead to the invocation of Article 5 would be taken by the North Atlantic Council on a case-by-case basis."
Nato's collective defence clause has only been activated once, when the members rallied behind the United States following the 9/11 attacks.
US President Joe Biden said that Article 5 was "a sacred obligation" among allies. Biden added: "I just want all of Europe to know that the United States is there."
Nato leaders agreed that China's military power presents a "systemic challenge" to the alliance, the first time such potentially inflammatory language has been applied to Beijing's armed forces.
Jens Stoltenberg, Nato's secretary general, said China's "AI and autonomous systems are changing the nature of warfare in a way never seen before".
The language in the summit's final communiqué, which will set the path for alliance policy, comes a day after the G7 issued a statement on human rights in China and Taiwan that Beijing said slandered its reputation.
The focus on Beijing will be seen as a victory for Biden's administration, which was pressing other leaders to adapt Nato capacities to counter China, whereas European leaders are more worried about the threat from Moscow.
UK Prime Minister Boris Johnson, who attended the summit, insisted that Nato did not want a Cold War with Beijing. Johnson said: "I don't think anybody around the table today wants to descend into a new Cold War with China. I think people see challenges. They see things that we have to manage together. But they also see opportunities and I think that what we need to do is do it together."
Johnson added that Biden would be taking "pretty tough messages" to Vladimir Putin when he meets the Russian leader in Geneva tomorrow. He said: "I'm always hopeful that things will improve with Russia but... I'm afraid that so far it's been pretty disappointing from the UK point of view."
Stoltenberg also said that the Nato community's "relations with Russia are at the lowest point since the Cold War".
Responding to the summit, Tobias Ellwood, chairman of the defence select committee, said he welcomed "Nato's continued engagement in the policy areas of hybrid threats, cyber and space".
"These are areas of increasing importance which the defence committee intends to explore within this parliament."
Looming large at the summit was also the scramble to complete Nato's hasty withdrawal from Afghanistan after Biden surprised partners by ordering US troops home by September 11 this year.
Recep Tayyip Erdogan, Turkey's president, said his country would expect "diplomatic, logistical and financial" assistance from the US if it was to maintain a presence in Afghanistan following the withdrawal of Nato troops.
Turkey is reported to have offered to protect Kabul's international airport after the departure of the Nato force.
Biden said he had a "very good" talk with Erdogan on the sidelines of the summit. However, he was last night running more than two hours late for his scheduled press conference. No explanation was offered by the White House.