Donald Trump: Mexican peso weakened by US President's 'We will build a wall' tweet

Mr Trump plans to unveil actions on national security starting Wednesday that are expected to include steps toward building a wall on the Mexican border

President promises a national security focus on Wednesday (Getty)

There are only so many tweets by President Donald Trump that the Mexican peso can handle.

Mr Trump, on Wednesday, is expected to unveil actions on national security, including an announcement to build a wall along the border between the US and Mexico.

He tweeted: “Big day planned on NATIONAL SECURITY tomorrow. Among many other things we will build a wall.”

The Mexican peso reversed earlier gains following the tweet, dropping to a session low against the US dollar, according to Bloomberg.

The currency weakened by 0.15 per cent on Wednesday to 21.56 peso to the US dollar.

Mr Trump’s twitter feed has become a problem for the Mexican economy.

The currency dropped to a record low of 22 pesos per dollar on 11 January after Mr Trump warned US car manufacturers would face a high tax for products made south of the border.

It was one of the worst-performing major currency last year, weakening 20 per cent against the dollar in the lead up to Mr Trump winning November’s presidential election.

Building a 2,000-mile wall along the Mexican border was one of Mr Trump key proposals.

The President has also insisted Mexico will pay for the wall, which the Mexican government has repeatedly rejected.

Later this week, Mr Trump is expected to announce immigration restrictions from seven African and Middle Eastern countries, including Syria, and Iraq.

He is also likely to halt access to the country for some refugees - until the a vetting process can be made more rigorous.