Burr said Wednesday that the committee has not seen any evidence that the activities favored either Republicans or Democrats.
But Burr also told reporters that the committee had "hit a wall" in attempting to verify the details of a salacious dossier about Trump's alleged exploits in Russian Federation, mostly because its author, former British spy Christopher Steele, had rebuffed the committee's efforts to speak with him about his sources and who paid for the compilation of the report.
The committee has been examining how fake accounts on Facebook and Twitter were used by Russians to promote propaganda and misinformation during the 2016 election.
"We have not come to any determination on collusion", Burr said. Burr said the panel and its staff have reached a "general consensus" that they trust the intelligence community's assessment that Moscow directed an influence campaign in the US election.
"We will share with you when we have exhausted every thread of intelligence, every potential witness that can contribute anything to this", he said.
Burr said he did not have a timeline on when the investigation will conclude, though he said somewhat wistfully that his "aspirational goal" was still to end by the end of year. Google has also been asked to testify.
"We don't release documents provided to our committee, period", said Burr. "I strongly suggest that you come in and speak with us".More news: Trailer Released For 'Oscar Pistorius: Blade Runner Killer' Movie
"Those offers have gone unaccepted", Burr said.
The Republican said the panel can not determine the dossier's credibility without understanding who paid for it and who contributed to the material.
The dossier, authored by former British spy Christopher Steele, includes unverified allegations about Trump's connections with Russian Federation and surfaced online in January.
Mr Burr said the panel has confirmed the findings of USA intelligence agencies - that Russian Federation had interfered in the election - but that one portion of the investigation has not yet closed. The panel also talked to everyone involved with the changing of the Republican platform on Ukraine, and Burr said the staff believed in what they were implementing. The company had already turned over the ads to the special counsel Robert Mueller. Warner emphasized the need for "an organized, whole-of-government approach" to address further meddling, and he also said the committee is working with social media entities to deal with foreign efforts to spread false information throughout the internet. But he added that the 2016 election demonstrated "the Russian intelligence service is determined, clever and I recommend every campaign and every elected official take this seriously".
Among those who have been questioned are former campaign chairman Paul Manafort, as well as Mr Trump's son-in-law and adviser Jared Kushner.
There are several public hearings on the horizon.
A Facebook spokesperson told BI early last month that the company was "unable" to release the ads "due to both federal law and the fact that investigations are ongoing with the relevant authorities".
New reports show Russian-linked Facebook ads specifically targeted our state, along with Wisconsin.