Washington (CNN) Donald Trump spotlighted his economic goals Thursday, using the third stop on his "thank you" tour to reassure Americans that he'd bring back jobs to the United States and pushed a message for companies and countries around the world: "Buy American, hire American."

"The American worker built this country and now it's time for American workers to have a government for the first time in decades answers to them," Trump said at his rally.

Trump used the Hawkeye state backdrop to officially re-introduce Terry Branstad Thursday as his pick to be the US ambassador to China during a rally in the Iowa governor's home state, a choice showcasing Trump's base of support among blue collar workers weary of trade deals as well as the important and fraught relationship the US has with the dominant Asian nation.

"The man I've chosen as our ambassador to China is the man who knows and likes China," Trump said. "And knows how to deliver results and he will deliver results just like he's been delivering results for 23 years for the great farmers and the people of Iowa."

Trump's transition team cited Branstad's experience in public policy, trade and agriculture as attributes that led to his selection as Trump's envoy in Beijing, as well as his pre-existing relationship to China's leaders.

"One of the most important relations we must improve, and we have to improve, is our relationship with China," Trump said at his rally in Des Moines. "The nation of China is responsible for almost half of America's trade deficit ... they haven't played by the rules and I know it's time they're going to start. We're all in this thing together, folks. We have to play by the rules, folks."

Trump has had a contentious relationship with China since his emergence in national American politics, blaming China for stealing US jobs and has threatened high trade tariffs against the country.

And in his speech, as he has done at rallies while he was campaigning, Trump has made China's alleged currency manipulation a regular issue.

Trump also broke protocol last week by chatting with Taiwan's President Tsai Ing-wen, who passed along her congratulations to the President-elect.

China views Taiwan as a renegade province and, since 1979, the US has acknowledged Beijing's claim that Taiwan is part of China, with US-China relations governed by a set of protocols known as the "one China" policy. So this means there are no formal diplomatic relations between the United States and Taiwan -- but Trump's decision to take Taiwanese President Tsai Ing-wen's call could pose problems for relations between the US and China

Branstad will confront important diplomatic challenges with China, including growing tensions over the disputed South China Sea, the implementation of the Paris climate change agreement, and the US and China's economic and trade relationship.

And China can make things complicated for the Trump administration. It could refuse to help slow the nuclear program of close ally North Korea, impose tariffs on US goods or make it more difficult for American businesses to operate in China.

Trump also highlighted other parts of his policy promises which appeared to highlight both his commitments to stricter trade laws as well as national pride. He vowed to crack down on employes who violate Visa rules, also saying that he was going to suspend immigration from places "where it cannot be processed or vetted."

"We want people coming into our country we want them coming in legally," Trump said at his rally. "There are going to be doors in the wall big beautiful doors."

Also during his speech, Trump also alluded to his comments last week where he suggested people who burn the US flag should be jailed or lose their citizenship. He said he'd be putting forward something soon "in the not so distant future."

"And to all veterans who wore the uniform before, I say to you now in behalf of a very grateful nation, thank you, thank you thank you ... We'll honor your service, your sacrifice," Trump said. "And that really begins with defending and respecting our American flag. I think you'll be liking some of the things we'll be putting forward in the not so distant future. You know what I mean?"

He took the time at the beginning of his speech to honor the late John Glenn, a US senator and astronaut from Ohio who died Thursday at the age of 95.

"When Pearl Harbor was attacked, one man who immediately enlisted to defend his country was John Glenn," he said. "For the next seven decades, he devoted his life to defending the American people ... he was a giant among men and a true American legend."

"We will honor his legacy by continuing to push new frontiers in science, technology and space," he said.