President Donald Trump will direct on Monday the US Trade Representative Robert Lighthizer to determine whether to investigate China's trade practices, which he had questioned even before he entered the White House.

The possible inquiry will be under Section 301 of the Trade Act of 1974 , which allows the US president to unilaterally impose tariffs or other trade restrictions to protect US industries from "unfair trade practices" of foreign countries.

Trump has alleged that China is engaged in unfair practices and claimed the Asian powerhouse is manipulating its currency to boost its exports – the same accusations were also directed to Germany and Japan.

He has also bemoaned China's trade surplus with the United States.

However, there is a growing belief among observers that Trump's interest in trade-related punitive measures against China is intertwined with his perception that China has not done enough to control the Democratic People's Republic of Korea (DPRK) and its nuclear weapons program.

Experts say that Trump's push for trade sanctions has been motivated by the deteriorating situation on the Korean Peninsula. US officials have denied such claims, but Trump's tweet history tells a different story.

Beijing has taken measures to alleviate Washington's worries about alleged uneven playing field in trade. When Chinese President Xi Jinping met with Trump in Florida in April, he emphasized that trade disputes could be settled through talks and discussions.

A 100-day plan was hammered out after their meeting, bringing US beef back to Chinese market in June and peace of mind to Trump – at least momentarily.

Despite ongoing talks between the two sides over how to sail through differences and concerns and the emergence of tangible outcomes from the plan, Trump has returned to Twitter to criticize China as tensions between Washington and Pyongyang ratchet up.

Below is a compilation of tweets by Trump about trade with China: