Washington, Sep 5 (IANS): US President Donald Trump spoke to two American astronauts, Peggy Whitson and Jack Fischer, upon their return from the International Space Station (ISS), the White House said.

The President on Monday congratulated Whitson and Fischer for their accomplishments, saying: "They make us all very proud," reports The Hill magazine.

"Exploration has always been at the core of who we are as Americans, and their brave contributions to human space flight have continued that great tradition."

Trump called Whitson an "inspiration to us all" after she set the US record for the most days spent in space by an astronaut at 665.

"Especially to young women interested in or currently pursuing careers in science, technology, engineering and math," Trump added.

Whitson and Fischer along with Russia's Fyodor Yurchijin, members of 52nd expedition to the ISS, landed at 7.21 a.m., on Sunday near a remote area in Dzhezkazgan, Kazakhstan.

Fischer and Yurchikhin both spent 136 days aboard the ISS.

In April, Trump spoke with Whitson to congratulate her after she broke the previous US record for cumulative days spent in space, The Hill magazine reported.

"I want to say that this is a very special day in the glorious history of American space flight," the Oresident said.

"Today, Commander Whitson, you have broken the record for the most total time spent in space by an American astronaut, 534 days and counting. That's an incredible record to break and on behalf of our nation and frankly, on behalf of the world, I'd like to congratulate you."

Russian cosmonaut Sergey Riazanski (Roscosmos), American Randolph Bresnik (NASA) and Italian Paolo Nespoli (European Space Agency), remain on the ISS, to be joined by three others on September 12.

The ISS, a 16-nation project representing an investment of more than $150 billion, currently comprises 14 permanent modules and orbits the Earth at a speed of more than 27,000 kph.