NASA is exploring ways to keep the International Space Station (ISS) in orbit without the need for Russian support. It doesn't see any present signs of Moscow withdrawing from the collaboration following the special military operation in Ukraine, a senior official said Monday.

Kathy Lueders, the head of the human spaceflight program of the agency, told reporters that operations on the research platform were proceeding "nominally" and "we're not getting any indications at a working level that our counterparts are not committed."

"That said, we always look for how do we get more operational flexibility and our cargo providers are looking at how do we add different capabilities," she continued.

While the US side of the ISS provides power and life support, Russia is responsible for propulsion and keeping the station floating, through the use of docked Progress spacecraft; it gives the station a periodic boost to maintain its altitude, about 250 miles (400 kilometers) high. 

Russia's space chief Dmitry Rogozin raised last week the prospect of withdrawing from the partnership following the US sanctions, which allows the 400-ton structure to crash to Earth while most likely not affecting his country since its orbit doesn't fly much over it.

Lueders said, "Northrop Grumman has been offering up a reboost capability, and you know, our SpaceX folks are looking at can we have additional capability."

The last Northrop Grumman Cygnus cargo vessel arrived at the ISS on February 21; it was the first to boast a capacity to "reboost" the outpost without the support of Russia.

On Friday, SpaceX boss Elon Musk responded to Rogozin's question about who would save the ISS from an uncontrolled de-orbit, by commenting with his company's logo.

However, Lueders stressed that "it would be very difficult for us to be operating on our own -- ISS is an international partnership that was created...with joint dependencies," adding that "as a team, we are looking at where we may have operational flexibilities."

"But... it would be a sad day for international operations if we can't continue to peacefully operate in space," she concluded.