Terms of Trade is a daily newsletter that unravels those involved in trade wars.

The European Union said that a preliminary trade agreement between US and China could violate the rules of the World Trade Organization, and lead to a legal action.

The trip to Washington of the EU trade commissioner, Phil Hogan, coincided with a ceremony at the White House on Wednesday, when US and China signed the first phase of their trade agreement. In separate comments at an event in the US capital, Hogan said that the two trading partners should stop "beating each other up."

For the past three days, Hogan, while in Washington, has been trying to convince the Trump administration to roll back its protectionism and work with EU to strengthen the WTO. He said that the first-phase agreement between US and China is a "result of managed trade" and is not a free trade agreement backed by the WTO.

The commissioner also said that his team will carefully examine whether it is mandatory for China to increase purchases of US goods and services by at least $ 200 billion over the next two years.

"We have not analyzed the document in detail, but we will do it, and if, of course, there is a problem with compliance with the WTO requirements, we will have to file lawsuits and defend our own economic interests, despite the fact that we did not want to develop the conflict," Hogan said at a conference on Thursday in Washington.

These comments suggest that any strain on US relations with China affect the rest of the world.

The US and EU are entering a trade dispute after Trump's deal with China.