US Secretary of State John Kerry demanded Russian President Vladimir Putin act immediately to deal with the separatists, and also ensure proper handling of the crash scene.
Correspondent: Jane Cowan, North America correspondent
Speakers: John Kerry, US Secretary of State; Dianne Feinstein, Democratic Chair of the Senate Intelligence committee; Lindsey Graham, Republican senator
JANE COWAN: As waves of shock and grief wash around the world, the US Secretary of State John Kerry appeared on five television networks one after the other.
He repeatedly stopped short of flatly stating Russia's responsible for the downing of the Malaysia Airlines Flight 17, but forcefully built the case for Russian involvement.
JOHN KERRY: Now we have a video showing a launcher moving back out into Russia with at least one missing missile on it. So we have enormous sort of input about this, which points fingers.
JANE COWAN: The Secretary of State's comments reflect Washington's growing anger with Russia over the crash.
JOHN KERRY: This is a moment of truth for Mr Putin and for Russia. Russia to step up and prove its bonafides, if there are any left, with respect to its willingness to put actions behind the words.
JANE COWAN: Pressure is building on the Russian president Vladimir Putin to rein in the rebels and actively support a transparent investigation.
The Democratic Chair of the Senate Intelligence committee, Dianne Feinstein.
DIANNE FEINSTEIN: This has become a huge human drama and I think the nexus between Russia and the separatists has been established very clearly.
So the issue is, where is Putin? And I would say, Putin, you have to man up, you should talk to the world, you should say- If this was a mistake, which I hope was, say it.
JANE COWAN: It's a delicate moment for the US president Barack Obama, under fire from critics like the Republican senator Lindsey Graham, who want him to come down harder on Vladimir Putin.
LINDSEY GRAHAM: He didn't call Putin the thug that he is. There's a battle of wills between the KGB colonel and the community organiser and the colonel is winning.
Indecision reigns. President Obama is trying to be deliberative, it comes off as indecisive; he's trying to be thoughtful, it comes off as weakness.
I'm suggesting European-American organised sanctions that go after Putin individually, the energy sector in Russia, the banking sector in Russia. I'm suggesting that we arm the Ukrainians so they can defend themselves. I'm suggesting we put more NATO troops surrounding Ukraine, that we rebuild the missile defence systems that Obama took down to let Putin know the path of least resistance is not to continue to dismember the Ukraine.
JANE COWAN: But in his round of television interviews, secretary of state Kerry resisted invitations to condemn the Russian leader.
JOHN KERRY: This is more complicated than just throwing names at each other and making declarations. Russia is working with us in order to try to deal with Iran's nuclear program, in helping to remove chemical weapons from Syria. So there has to be a continued effort to find a way forward.