Sasse has brought Nebraska agricultural leaders to Washington to help make the case, including to a Thursday meeting with Mexican ambassador Gerónimo Gutiérrez.
But Trump said he would simply up levies on vehicle imports from the European Union in retaliation - a potentially painful blow for "car nation" and export champion Germany.
"It's a conundrum, really, because you do not want 100 senators and our counterparts in the House doing basically any trade initiative".
Sasse last week gave a number of network news interviews on the subject, and he said he has counseled the president on the issue.
The two also met with Japan's Minister of Economy, Trade and Industry of Japan Hiroshige Seko, and all three pledged in a statement afterward to work together to fight dumping that hurts jobs and industries around the world. "I think that they know that kids are playing these games and [that] children do have ready access to violent video games".
Fellow Nebraska Republican Sen. The video was uploaded unlisted to The White House YouTube channel.
Ex-White House Communications Director Hope Hicks arrives to meet behind closed doors with the House Intelligence Committee
When he initially decided on the plan, he reportedly said that the 25 percent tariff on foreign steel and 10 percent tariff on foreign aluminum would apply to all countries, because otherwise, everyone would ask for an exemption.
She also warned the Trump administration's tariffs could provoke retaliations from other countries.
U.S. Reps. Don Bacon and Adrian Smith of Nebraska have signed on to letters urging the president to reconsider. At the same time, The Australian Financial Review reports, Aussie steel and aluminum exports will also be exempted, citing confidence in Canberra that a negotiating process will be a mere "formality".
He started his career working as an investment banker in New Zealand and from 1999 to 2002 was chief executive of then majority US-owned Carter Holt Harvey, a large New Zealand forestry and paper-making company, having earlier been the chief financial officer.
The developments Thursday cap a week of frenzied lobbying by Canada, and come after the seventh round of NAFTA talks, which concluded Monday.
"Should restrictions be imposed on Canadian steel and aluminum products, Canada will take responsive measures to defend its trade interests and workers", she said.
Bacon, a member of the House Agriculture Committee, said the USA needs to remain in NAFTA. Unfortunately, the problem of easily available firearms is not being looked at close enough and that is the real problem and primary cause of gun violence in the US.