NATO will continue to cooperate with Russia on projects related to Afghanistan, despite the alliance's vow to suspend most ties with Moscow because of its annexation of Crimea, diplomats said Wednesday.
Meanwhile, NATO's top official warned that Russia would commit a "historic mistake" if it invaded Ukraine.
On Tuesday, NATO foreign ministers decided to suspend all "practical" military and civilian cooperation with Russia, in protest over its annexation of Ukraine's Crimea peninsula. The United States and the European Union previously announced a series of sanctions targeting Russian officials and institutions and threatened to strengthen those measures if Russia moved into eastern Ukraine.
Secretary-General Anders Fogh Rasmussen reiterated that there was no sign that the Russian army was reducing its buildup along Ukraine's eastern border.
"If Russia were to intervene further in Ukraine ... that would lead to further international isolation of Russia, it would have far-reaching consequences for relations between Russia and the Western world. It would be a miscalculation with huge strategic implications," he told reporters at the end of a two-day meeting of foreign ministers in Brussels.
The ministers from NATO's 28 member states decided to strengthen the defenses of alliance members that feel menaced by Russia's buildup. They also said the alliance would boost cooperation with Ukraine to strengthen that nation's defence capabilities.
The U.S. has deployed six F-15 fighters to reinforce air patrols over the Baltics, along with 12 F-16s to Poland. It also dispatched a destroyer, the USS Truxtun, to take part in exercises with allies in the Black Sea.
"And more U.S. support is on the way," Secretary of State John Kerry said on Monday without elaborating.
Moscow has said it has no intention of invading eastern Ukraine and has dismissed suggestions that its forces represent a threat to any NATO nation. On Tuesday, Russian Defense Minister Sergei Shoigu said Russia wanted a political settlement to the crisis.
NATO reacted in a similar way to Russia's incursion into Georgia in 2008. The alliance cut ties with Russia and declared there could be no business as usual with Moscow. That freeze lasted for more than a year but was quietly abandoned as cooperation with Moscow intensified in Afghanistan and elsewhere.
Diplomats attending the talks in Brussels said the current suspensions would likely affect joint counterterrorism exercises, naval anti-piracy patrols and cooperation in coping with natural disasters.
But they would not affect cooperation with Russia in the Afghan war, said a senior envoy who spoke on customary condition of anonymity.
NATO would continue using a key overland supply route through Russia for its forces in Afghanistan known as the Northern Distribution Network, which carried about 40 percent of all alliance supplies to Afghanistan in 2013. The rail route, leading from northern Afghanistan to Poland and the Baltic nations, is considered crucial because it is safer than the ambush-prone alternative route through Pakistan.
The diplomat said cooperation in equipping and training the Afghan air force in the use of Russian helicopters also would continue, as would joint efforts to fight the Afghan drugs trade.
"These are issues that are vital to both sides, so it's natural to continue working together," the official said.
In Washington, a Defense Department official said there had been no problems with Russia when it came to moving freight through the northern route since the outbreak of the Ukraine crisis.
"Everything is flowing well," said the official, who asked not to be identified because he was not authorized to speak to the media on this topic.
But he noted that even if the Russians did cut off the supply route, "it wouldn't stop our operations in Afghanistan, but it would be more expensive ... and more challenging" to ship via other routes.
Unlike for NATO as a whole, only about a quarter of all supplies for U.S. forces in Afghanistan flow through the northern route, according to the Pentagon.
Stars and Stripes reporter Jon Harper in Washington contributed to this report.