NASA chief Jim Bridenstine on Friday praised the Russian space programme and said he expected a new crew to go to the International Space Station in December despite a rocket failure.
"I fully anticipate that we will fly again on a Soyuz rocket and I have no reason to believe at this point that it will not be on schedule," he told reporters in Moscow.
The NASA administrator spoke to reporters at the US embassy in Moscow a day after a Soyuz rocket failure forced a two-man crew to make an emergency landing in Kazakhstan.
It was the first such incident in Russia's post-Soviet history -- an unprecedented setback for the country's space industry.
Bridenstine, who is visiting Russia and Kazakhstan for the first time since his appointment as NASA head this year, observed the launch from the Baikonur cosmodrome with his Russian counterpart Dmitry Rogozin.
He said he was "confident" that a new manned mission to the ISS would go ahead as planned in December, praising the "wonderful relationship" between the Russian and US space agencies.
The next Soyuz launch had been scheduled to take a new crew to the ISS on December 20.
The Russian space agency said on Friday it may bring forward the launch of the next mission to the ISS.
Looking at times emotional, the NASA chief praised "the resilience" of the Soyuz rocket.
"Not every mission that fails ends up so successful," he said.
He added he had discussed the accident with US Vice President Mike Pence but not with US President Donald Trump.
He said he had also spoken to US astronaut Nick Hague who appeared in high spirits despite the ordeal. "He was very funny," he said.
The NASA chief played down tensions between the two countries, saying space remained an area of cooperation.
"We can both do more in space together than we can do alone," he said, adding his relationship with Russian space agency chief Rogozin was "very solid."
When asked about the accident, Trump said on Thursday that he was "not at all worried" that Americans had to rely on Russians to go to space.