The pair landed about 20 kilometers (12 miles) east of Dzhezkazgan, Kazakhstan. He added that the president is receiving regular updates about the situation.
The agency said search-and-rescue teams were en route to the landing location and were in contact with the two crew members.
Thursday's problem occurred when the first and second stages of a booster rocket, launched from the Soviet-era cosmodrome of Baikonur in the central Asian country, were separating, triggering emergency systems soon after launch.
They were to dock at the orbiting outpost six hours later but the booster suffered a failure minutes after the launch.
Astronaut Alexander Gerst, who is one of three crew members now aboard the International Space Station, captured the dramatic failed launch of the Russian Soyuz rocket in a stunning series of photographs.
The onboard astronauts were certainly aware that something was not right because they reported feeling weightless when they should have felt pushed back in their seats. The city is about 450 kilometers from the Russia's Baikonur space center, which Russian Federation operates through an agreement with the Republic of Kazakhstan.
During the descent the two astronauts, who were going up for a 6 month stay on the ISS, experienced G-force pressure of 7G.
The taxi service to the orbiting International Space Station (ISS) is taking no passengers until further notice. "What we've got to do is we've got to very dispassionately allow the investigation to go forward without speculation, without rumor, without innuendo, without conspiracy". It can hold a crew of up to six people.
Two spacewalks planned for later this month have been postponed indefinitely, as Mr Hague was supposed to be one of the spacewalkers. Hague was supposed to be one of the spacewalkers.
Russian Federation was forming a state commission to investigate the Soyuz launch incident, Nasa said.
But soon after the landing, USA and Russian officials said that rescue forces were in contact with the astronaut and cosmonaut. The spacecraft has been the sole means of bringing humans to the space station since the end of the U.S. Space Shuttle program, but commercial providers aiming for manned spaceflight are increasingly nipping at Russia's heels. But it will need to be staffed before SpaceX or Boeing launches its new crew capsules next year, Todd said. The space station and its crew depend heavily on missions supported by the rocket.
The launch failure follows close on the heels of another Soyuz issue, in which a hole was discovered August 29 on the MS-09 spacecraft that delivered the most recent crew to the space station. Borisov added that Russian Federation will fully share all relevant information with the U.S.
It was not immediately clear what caused the failure.
Earlier this week, Bridenstine emphasized that collaboration with Russia's Roscosmos remains important.
Collaboration between the U.S. and Russian space agencies has largely steered clear of geopolitical controversies, despite a standoff between Washington and Moscow that has continued since Russia's annexation of the Black Sea peninsula of Crimea from Ukraine in 2014 and allegations of Russian meddling in the 2016 USA presidential election.
Hague and Ovchinin were to join the current three-person crew on the International Space Station to perform research experiments. Russian Federation stands to lose that monopoly in the coming years with the arrival of SpaceX's Dragon v2 and Boeing's Starliner crew capsules.
Dmitry Rogozin, a firebrand nationalist politician who this year was appointed by Putin to head Roscosmos, said a "thorough investigation" was needed after the failed launch.
He added that it will take about a week for the crew to fully recover.
Rescue crews are now heading towards the emergency landing site in the barren Kazakh steppe to provide support for the crew.
The rocket took off from Kazakhstan and was on its way to the International Space Station.
In recent years, Russia's space programme has faced a number of technical failures - 13 since 2010.
Glitches found in Russia's Proton and Soyuz rockets in 2016 were traced to manufacturing flaws. The Russian space agency also sent 70 rocket engines back to production lines in 2016 to replace broken parts.