Sen. Susan Collins reiterated her confidence Wednesday that the intelligence committee she serves on will do whatever it takes “to get to the bottom” of Russia’s involvement in the 2016 presidential election and the probing of critical infrastructure.

“All of us are determined to get the answers,” Collins, a Republican, said on Maine Public’s “Maine Calling” radio program. “I am confident that since it is a completely bipartisan investigation with full-time staff that we will get to the bottom of this and I will encourage that there will be some public hearings as well as the closed hearings we are doing now.”

Collins, who serves on the intelligence committee along with Maine’s other senator, Angus King, said she is among many members of the committee who intend to have President Trump’s former national security adviser, Michael Flynn, testify before them. Flynn resigned Feb. 13 after misleading Vice President Pence about the content of his pre-inauguration conversations with the Russian ambassador to the United States.

King, an independent who caucuses with the Democrats, told the Portland Press Herald on Feb. 14 that the committee is extending its investigation to include Flynn. King told National Public Radio last week that the committee intends to talk to Flynn.

“We’ve already begun identifying witnesses and documents and the staff who are going to work on this, so we’re underway,” King said.

Collins was asked Wednesday whether the committee will subpoena Trump’s tax records, which he has refused to release. “I don’t know whether we will need to do that,” she said. “If it is necessary to get the answers then I suspect that we would.”

Collins said the committee’s investigation includes contacts between Russian officials and the various presidential campaigns, Russia’s hacking and attempted hacking of the Democratic and Republican National Committee databases, and “attempts by Russia to probe our natural gas pipelines, our critical infrastructure.”

Some Democratic lawmakers have expressed concern about the slow pace of House and Senate intelligence committee investigations of the Russia ties. Rep. Chellie Pingree, a Democrat representing Maine’s 1st Congressional District, co-sponsored a bill last week to create a bipartisan, independent commission to take over the investigation. “Part of our motivation has been that it feels as though they have been dragging their feet,” she told the Press Herald.

But Collins and King have said their committee is doing its job and has the competence and intention to see a thorough investigation. “We’re not going to exclude anyone from our review, and it will be through, accurate, bipartisan and in-depth,” Collins told Maine Public.