BRUSSELS -- U.S. Defense Secretary Jim Mattis says Russia must "prove itself" before Moscow can return to "a partnership of sorts with NATO."
Mattis's remarks on February 16 at the end of a two-day NATO defense ministers meeting in Brussels are seen as easing fears in some European capitals that U.S. President Donald Trump's administration might relax U.S. pressure on Russia over its aggressive actions as part of an effort to build a closer relationship with Moscow.
Mattis said Russia "has to live by international law just like we expect all mature nations on this planet to do."
He noted that NATO political leaders will try to find common ground with Moscow but said "we are not in a position right now to collaborate on a military level."
NATO cut some military ties with Russia, but did not cut political ties with Moscow after Russia invaded and illegally annexed Ukraine's Crimean Peninsula in 2014.
Speaking the same day in Bonn, U.S. Secretary of State Rex Tillerson told Russian Foreign Minister Sergei Lavrov that the Kremlin must adhere to its commitments on Ukraine if there is to be cooperation between Moscow and the Trump administration.
The Western alliance has held five NATO-Russia Councils, but little progress has been made in improving relations.
Mattis also spoke on February 16 about allegations that Russia interfered in the 2016 U.S. presidential election, and was now trying to interfere in the 2017 French presidential and German parliamentary elections -- saying "right now I would just say there is very little doubt that they have either interfered or they have attempted to interfere in a number of elections in democracies."
Russian Defense Minister Sergei Shoigu said on February 16 that Russia is prepared to improve ties with the Pentagon, but said attempts by Washington to seek cooperation from a "position of strength would be futile."
Increased Black Sea Presence
After the ministers' meeting, NATO Secretary-General Jens Stoltenberg said the alliance will increase its naval presence in the Black Sea, including conducting war games with land and air troops already there.
He insisted, however, that the move was not intended to provoke Russia.
"We will have an increased presence in the Black Sea, but it will be measured, it will be defensive, and it will in no way be provoking any conflict or escalating tensions," Stoltenberg said.
A NATO official, speaking on condition of anonymity, told the AFP news agency that the action was taken to deal with Russia's military buildup in the Black Sea.
NATO allies Turkey, Bulgaria, and Romania share the Black Sea coast, as do Ukraine and Georgia.
Russia seized the Black Sea peninsula of Crimea from Ukraine in 2014 and has troops in Georgia's breakaway coastal region of Abkhazia, which Moscow considers an independent state.
With reporting by RFE/RL's Rikard Jozwiak in Brussels, Interfax, AP, AFP, and TASS