OTTAWA – U.S. Trade Representative Robert Lighthizer defended American President Donald Trump's approach to tariffs Thursday, amid questions from both Republican and Democratic Senators about the impact being felt by the retaliatory tariffs that countries like Canada have imposed on U.S. goods.

American senators on a subcommittee of the U.S. Senate Committee on Appropriations related to commerce spent the morning grilling him about the current U.S. trade policy and concerns over where Trump’s approach to trade could take them.

Several senators used their questions to highlight how their states are being hurt by the retaliatory tariffs from Canada and other nations, including auto companies in Tennessee, which Republican Sen. Lamar Alexander represents.

Speaking to the impact being felt by small businesses, including New Hampshire lobster fishers, Democrat Sen. Jeanne Shaheen asked Lighthizer to explain the administration's plan.

"It's not just the agriculture sector, I am hearing from high-tech, value-added manufacturing companies about the negative effects of the administration's trade policies," she said.

"Unfortunately I worry that if we continue in this direction, this will be just the tip of the iceberg, and that if left unchecked, the trade war will have dire ramifications for the American economy."

In response to one of Shaheen’s questions, Lighthizer said both he and Trump are "very sympathetic" and said it is not their plan to have these companies feel the brunt of the change in trade policy.

Lighthizer said the aim of the shift is "designed to make the U.S. stronger and richer, and help our exports, and help all American businesses." He went on to say that in some trade disputes, namely with China, it will take time to resolve.

On Tuesday, Trump took to Twitter to champion how "tariffs are the greatest," and pledged that "all will be great." Later that day his administration announced their intention to offer a $12-billion bailout to help farmers hurt by tariffs.

Questioning national security argument

In those same tweets, Trump contradicted his own administration's stated national security justification for steel and aluminum tariffs, saying tariffs are imposed on countries who don't negotiate fair deals with the U.S.

In June when U.S. Secretary of Commerce Wilbur Ross announced the U.S. would be levelling a 25 per cent steel tariff and 10 per cent tariff on aluminum against Canada among other countries, he cited section 232 of the U.S. Trade Expansion Act, which handles trade matters considered a threat to national security.

At the time the U.S. tariffs were announced, various Canadian officials scoffed at the national security assertion, calling it insulting and "difficult to fathom."

This was something Rhode Island Sen. Jack Reed picked up on, repeatedly asking Lighthizer to explain how Canada specifically is a threat to national security.

"This is a country who has been with us every step of the way… are they a national security threat to the United States?" he said.

Lighthizer said that yes, Canada "absolutely" is.

Defending this position Lighthizer said that: "Nobody's declaring war on Canada or saying they are an unfriendly neighbour, they’re obviously not, they’re a great ally and certainly one of America's closest friends and closest trading partners, but if you decide that you need to protect an industry, you can't be in a position where the protection is of no value."

Republican Sen. For Maine Susan Collins also questioned whether the U.S. was risking "doing tremendous damage," to the American steel and aluminum industries by using the national security justification.

NAFTA nearing end

Lighthizer also faced questions about the state of the North American Free Trade Agreement renegotiations.

He told the subcommittee that the talks have been happening at a rapid pace, and that they are close to being finished.

"Hopefully we are in the finishing stages of achieving an agreement in principle that will benefit America’s workers, farmers, ranchers, and businesses," he said.

Though, he also stated that both he and Trump are of the belief that: "The United States is far better off in bilateral deals," citing the leverage having the biggest market brings.

His comments come a day after Foreign Affairs Minister Chrystia Freeland and other ministers met with their new Mexican counterparts to discuss trade. According to a Canadian Press report, Freeland expressed optimism at the three countries moving ahead with renegotiating the trilateral deal.