Would send cease-and-desist letters to China: Donald Trump

He further added that he would send such letter to other countries too, asking them to "stop ripping us off"

In his fresh anti-China tirade, Republican presidential frontrunner Donald Trump has said if elected to the White House he would send "cease-and-desist" letters to China and other nations that are "ripping us off".

Trump said he would send such letters "to China to stop ripping us off. I would be sending them to other countries to stop ripping us off. I'd send them to Mexico."

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"Look, our country is going to hell. We have a problem with China. We have a problem with Japan. We have a problem with Mexico both at the border and in trade," he said during a townhall in South Carolina.

He said this when asked about the cease-and-desist letter he sent to his Republican rival Ted Cruz and whether he would do the same if elected as the US president in November.

Trump said he would appoint smart businessmen to negotiate trade policies with China. "I want the greatest negotiators. We can't lose $505 billion next year with China," he said.

"We have the greatest business people in the world in this country. We don't use them. We use political hacks to negotiate with China, with Japan," Trump said.

During the townhall, Trump had a tough time defending his previous remarks calling the last Republican president George Bush a liar for going into war with Iraq.

"Going into Iraq may have been the worst decision anybody has made, any president has made in the history of this country. That's how bad it is," he said.

"He went into Iraq. He started something that destroyed the Middle East. And I said, 'Don't go in because you're going to ruin the balance in the Middle East; you're going to have a total imbalance; you're going to have Iran taking over Iraq.' Everything I said turned out to be true," Trump claimed.

Trump even claimed that he opposed the Iraq war from the "very beginning" and that it started the whole destabilisation of the Middle East.

"It started ISIS (Islamic State). It started Libya. It started Syria. That was one of the worst decisions ever made by any government at any time," he insisted.

"We have spent $2 trillion in fighting Iraq. Thousands of lives. We have wounded warriors," he said.