On Capitol Hill in Washington, Democrats have collectively criticised the Trump administration in the aftermath of General Michael Flynn's resignation as National Security Adviser.
Representative Elijah Cummings says an independent investigation is imperative.
"Do you hear the silence? This is the sound of House Republicans conducting no oversight of President Trump. Zero. That is what it sounds like when they abdicate their duty under the constitution."
General Flynn resigned after it emerged he misled the White House about his contact with Russia's US ambassador prior to Mr Trump's inauguration.
He initially denied discussing Russian sanctions while Barack Obama was still president.
And when claims contradicting that were made, Vice President Mike Pence publicly backed him earlier this month.
"They did not discuss anything having to do with the United States' decision to expel diplomats or impose a censure against Russia."
But US officials with access to intercepted communications confirmed General Flynn had, in fact, discussed sanctions.
That forced him to change his story, conceding he gave what he called "incomplete information" about his calls with the ambassador.
White House spokesman Sean Spicer says General Flynn lost President Donald Trump's trust.
"We have been reviewing and evaluating this issue with respect to General Flynn on a daily basis for a few weeks, trying to ascertain the truth. We got to a point, not based on a legal issue but based on a trust issue, where the level of trust between the President and General Flynn had eroded to the point where he felt he had to make a change. The President was very concerned that General Flynn had misled the Vice President and others. He was also very concerned, in light of sensitive subjects dealt with by that position of security advisers like China, North Korea and the Middle East, that the President must have complete and unwavering trust for the person in that position."
House of Representatives Speaker Paul Ryan says dropping the adviser was the correct decision.
"Security is, perhaps, the most important function or responsibility a president has. And I think the President made the right decision to ask for his resignation. You cannot have a national-security adviser misleading a Vice President and others. So I think the President was right to ask for his resignation. And I believe it was the right thing to do."
Democrats claim General Flynn broke the law.
House Minority Leader Nancy Pelosi is echoing calls for an inquiry.
"The American people have a right to know the truth. We see the consequences that can be dangerous to our national security. We want to know by what authority did General Flynn have these conversations and who did he report to after that."
Sean Spicer denies allegations President Trump instructed General Flynn to discuss sanctions with Russia.
"No, absolutely not. No, no, no. That ... no, and there is no ... that's never ... I think the President had no problem with the fact that he acted in accord with what his job was supposed to be doing. He had an ability to talk about issues that were of importance, whether it was that or the 30 other countries that he spoke to. That was part of his job. This was an act of trust. Whether or not he actually misled the Vice President was the issue. And that was ultimately what led to the President asking for and accepting the resignation of General Flynn. That's it, pure and simple. It was a matter of trust."
Russian officials have declined to discuss whether they were aware of the discussions.
The spokesman for President Vladimir Putin, Dmitry Peskov, calls it an internal matter.
"We don't want to comment on this in any way. These are internal matters of the Americans. These are internal matters of President Trump's administration. This is not our concern. Regarding this matter, we have commented on this several times, answering your question, and have nothing to add at this moment."
US Democratic Representative Elliot Engel says the matter is still not resolved.
"His departure raises more questions than it answers. What promises did General Flynn make to Putin's ambassador, and who else was involved? How deep were the connections between Russia and President Trump's campaign prior to the election? Why did the White House ignore the warnings of the Justice Department and allow someone subject to Putin's blackmail to remain in a critical national-security role?"
