President-elect Donald Trump announced Jamieson Greer as his pick to serve as the next US trade representative.

Greer is no stranger to the role, having served as chief of staff to Robert Lighthizer, the trade representative during Trump’s first term. At the time, the administration implemented across-the-board tariffs on China and other countries, as well as signed onto the US-Mexico-Canada Agreement (USMCA).

Trump has routinely referenced the passage of the USMCA trade agreement, which replaced the North American Free Trade Agreement or NAFTA, as a political victory and a highlight of his presidency.

“Jamieson will focus the Office of the US Trade Representative on reining in the Country’s massive Trade Deficit, defending American Manufacturing, Agriculture, and Services, and opening up Export Markets everywhere,” Trump said in a Tuesday announcement that lauded Greer as having “played a key role during my First Term in imposing Tariffs on China and others to combat unfair Trade practices, and replacing the failed NAFTA deal with USMCA, therefore making it much better for American Workers.”

If confirmed by the Senate, Greer will assume the role as Trump is expected to pursue an ambitious trade agenda.

Since winning the election, Trump has already promised to implement new tariffs on Mexico, Canada and China on the first day of his administration – until, he said, the countries prevent the flow of illegal immigrants and drugs across the border.

On the campaign trail, Trump had repeatedly said he will impose tariffs of either 10% or 20% on every import coming into the US, as well as a tariff upward of 60% on all Chinese imports.

The president-elect has described tariffs as a multi-use tool that can be used to punish other countries for unfair trade practices, boost American manufacturing and bring in billions of dollars to help pay for the extension of tax cuts he signed into law during his first administration.

The threat of tariffs could also be used as a negotiation tactic, as Trump has pledged to renegotiate the USMCA.

Greer, speaking on other countries’ trade and tax policies, told The New York Times in June that “if you level out that playing field, it makes it so that Americans don’t have to compete unfairly.”

He has most recently worked as a partner on the international trade team at law firm King & Spalding, according to his company bio. In that role, he has covered cases on trade policy and trade agreement enforcement.

He previously focused on trade-related matters in private practice and served in the US Air Force Judge Advocate General’s Corps, during which he deployed to Iraq, according to the bio.