Lighthizer, who has assailed some Republicans for being too pro-free trade, told the Senate panel earlier this year that the USA should have an "America-first trade policy".
"Right now, we're in a tough patch, and we're trying to get a trade policy squared away", Roberts said.
US President Donald Trump's nominee for US Trade Representative - a key position in renegotiations of the NAFTA - has passed a key hurdle in the US Senate.
In an 82-14 vote, the Senate approved Lighthizer as USA trade representative, to assume a major role in trade talks with other countries under Trump's "America First" agenda.
But Lighthizer won support from both Republicans and Democrats in the Senate on Thursday, with a 82-14 vote to confirm his nomination.
The Senate has voted to confirm President Donald Trump's nominee to serve as USA trade representative, despite clear frustration among some Republicans with the administration on trade.
Beyond Nafta, Mr. Lighthizer is expected to help Mr. Trump flesh out the "America First" trade policy that was a main plank of his nationalist presidential campaign.
The Senators were apprehensive that Lighthizer did not fully understand the complex problems in renegotiating the North American Free Trade Agreement (NAFTA).
"We can do better in negotiating our trade agreements and stronger in enforcing our trade laws", he said.
His nomination sends another signal that the Trump administration intends to upend decades of US policy and act aggressively to block imports when it deems other countries to be acting unfairly. They expect him to pursue a harder line on what he sees as predatory trade behavior, particularly by China, but to avoid upending the global free trade order.
"If you look at the trade deficit as an indicator - not the only indicator but an indicator - China is a good part of our problem", Lighthizer said during the hearing in mid-March.
Not all Republicans are enthusiastic.
Republican Senator John McCain and Ben Sasse had written a letter Tuesday opposing Lighthizer's nomination.
Some of Lighthizer's most vocal support has come from Democratic lawmakers. Blocking or taxing imports would raise prices of imports for American consumers and provoke retaliation. "By eliminating those unnecessary regulatory barriers to U.S. insurance trade through the Covered Agreement, U.S. insurers will be able to compete fairly in the European Union again".
Some Democrats, while critical of Trump's views on trade, said they were confident Lighthizer would work to help USA workers.
Lighthizer won't be the administration's only trade policy heavyweight. President Gary Cohn, who runs the White House National Economic Council, and trade hawks like economist Peter Navarro, who runs a newly created Office of Trade and Manufacturing Policy. He also served as a deputy U.S. Trade Representative under President Ronald Reagan, earning a reputation as a hard-nosed negotiator, and he has political experience from working as a senior aide to Senate Finance Committee Chairman Bob Dole.