The two leaders will meet for the first time in person on October 11 when Russia launches NASA Astronaut Nick Hague and Russian Cosmonaut Alexey Ovchinin to the space station from the Baikonur Cosmodrome in Kazakhstan. As magical as space is, low Earth orbit is a unsafe place, and even the ISS isn't immune to dangers like cosmic radiation or micro-meteorite impacts.
The Soyuz MS-08 carrying Russia's Oleg Artemyev and Nasa's Drew Feustel and Ricky Arnold touched down at 5.44pm Kazakh time (1144 GMT).
NASA's statement comes after Roscosmos general director Dmitry Rogozin said the investigation has ruled out a manufacturing defect.
NASA has issued an update that appears to downplay the leak in the station's atmosphere that was discovered in late August.
Last month the Russian daily Kommersant reported that an investigation had probed the possibility that U.S. astronauts deliberately drilled the hole in order to get a sick colleague sent back home - something Russian officials later denied.
According to Dmitry Rogozin, who was placed under USA sanctions over the Ukraine crisis in 2014, said he experienced difficulties in collaborating with NASA and other USA agencies to solve out the issue of the ISS hole.More news: India to deport Rohingya to Myanmar, despite United Nations concern
Feustel, Arnold and Artemyev launched to the space station on March 21 and will have spent 197 days in space as members of Expeditions 55 and 56 when they return home.
NASA said a spacewalk was being tentatively planned for November to gather more information.
A trio of scientists who spent almost 200 days in space have now landed safely back on Earth after departing the International Space Station.
Currently, Expedition 57 continues station research and operations with a crew comprised of Serena Aunon, Chancellor of NASA, Alexander Gerst of ESA (European Space Agency) and Sergey Prokopyev of Roscosmos.
Astronaut Andrew Feustel, who has two science degrees from Purdue University, also moonlight's as a musician and just released a music video for a song from ISS.
"To me and for our nation it was really important (those lessons) weren't lost", he said.