(Reuters) - Clete Willems, a top trade official in President Donald Trump’s White House who has been a key figure in negotiations with China, is leaving in the coming weeks to spend more time with his family after the birth of a new baby, he said on Friday.

FILE PHOTO: U.S. trade delegation member Clete Willems leaves a hotel for talks with Chinese officials in Beijing, China February 13, 2019. REUTERS/Jason Lee

Willems, a deputy to Trump’s top economic adviser Larry Kudlow, is departing his post as trade talks between the world’s two biggest economies drag on past the initial goal of a deal by the end of March.

He will be succeeded by Kelly Ann Shaw, currently Trump’s senior director for international trade, investment and development, Kudlow said.

“As my top international deputy, Clete has helped the president change the global conversation on trade and make exceptional progress in negotiations with China, the EU, Korea, and reform of the international trading system,” Kudlow said in a statement.

Willems has been a constant presence during U.S. talks with China, which have faced stumbling blocks over Washington’s demands for a strong enforcement mechanism and for China to change its habits on intellectual property and technology transfers from American companies doing business there.

The talks are being led by U.S. Trade Representative Robert Lighthizer and Treasury Secretary Steven Mnuchin. Willems, who has made repeated trips to Beijing as part of the U.S. delegation, served in a more behind-the-scenes role.

The Wisconsin native told Reuters that he and his wife had just had a second child and made clear he was not leaving the White House because of any dissatisfaction with his work.

“I love my job, but I love my family, too,” he said.

Willems expressed pride in the administration’s work on trade.

The 39-year-old lifelong Republican, known for a cheerful smile and colorful socks, got his start in politics and in trade policy working for Representative Paul Ryan, driving the then-lawmaker around their home state and rising from intern to a top legislative aide.

He studied chemical engineering as an undergraduate at the University of Notre Dame in Indiana and then law at Georgetown University, studying at night while working for Ryan during the day.

Willems worked as a lawyer for the office of the U.S. Trade Representative, including a stint in Geneva, before joining the Trump administration. In addition to working on China trade issues, he served as the U.S. sherpa for the G7 and G20 in his role as deputy assistant for international economic affairs.

He has accepted a position in the private sector, a White House official said.