Mr Lyons told the BBC Good Morning Ulster programme: “He very clearly takes a different view than unionists would on many things.
“He has worked closely together with Friends Of Sinn Fein in America, attending their events.
“He has planted trees in memory of hunger strikers and spoken glowingly about them. He commended president (Michael D) Higgins for not attending a service to commemorate the centenary of Northern Ireland.
“He has said he is hopeful there will be a united Ireland in his lifetime.
“So, yet again we are dealing with more American politicians who are very much one-sided.
“That adds to the challenge, but we are up for that, and letting them know about the issues that the protocol is causing.”
Mr Lyons said his party would be stressing the difficulties the Northern Ireland Protocol is causing during meetings with the US delegation.
He said: “Rather than protecting the Good Friday Agreement and successor agreements, the protocol actually damages them.
“It is causing economic difficulty, it is causing societal problems and it is very clearly causing divergence of trade, and of course it is causing political instabilities.
“So we need to get that message across that the protocol is not protecting the Good Friday Agreement and that is why we need this issue dealt with quickly.”
Mr Lyons added: “I know that is not going to be an easy task. I previously met with congressman Neal in Washington and reminded him and Nancy Pelosi of the problems with the protocol.
“I think it’s fair to say that they weren’t interested. We are going to have a particular challenge with congressman Neal.”