Donald Trump vows to crush Isis when he becomes the 'unpredictable president'

Donald Trump said if he is president the US will act "more unpredictable" in order to defeat Islamic State (Isis), as he delivered his much anticipated foreign policy speech. The Republican frontrunner said he aims to put "America first" in his policy and replace "chaos with peace" while rebuilding the US economy by investing in the military equipment and making sure "our military dominance [is] unquestioned".

In a more downbeat speech from Trump than previously seen during his campaign trail, he said: "I will seek a foreign policy that all Americans, whatever their party, can support, and which our friends and allies will respect and welcome. The world must know that we do not go abroad in search of enemies, that we are always happy when old enemies become friends, and when old friends become allies. To achieve these goals, Americans must have confidence in their country and its leadership again.

"Many Americans must wonder why our politicians seem more interested in defending the borders of foreign countries than their own. Americans must know that we are putting the American people first again. On trade, on immigration, on foreign policy – the jobs, incomes and security of the American worker will always be my first priority."

Discussing his long-term plan to halt and control the spread of radical Islam, Trump said: "We should work together with any nation in the region that is threatened by the rise of radical Islam. But this has to be a two-way street – they must also be good to us and remember us and all we are doing for them.

"The struggle against radical Islam also takes place in our homeland. There are scores of recent migrants inside our borders charged with terrorism. For every case known to the public, there are dozens more. We must stop importing extremism through senseless immigration policies.

"And then there's Isis. I have a simple message for them. Their days are numbered. I won't tell them where and I won't tell them how. We must as, a nation, be more unpredictable. But they're going to be gone and gone very, very soon."

Trump added one of his main goals if he became US president is to "live peacefully and in friendship" with China. He added: "Fixing our relations with China is another important step towards a prosperous century. China respects strength, and by letting them take advantage of us economically, we have lost all of their respect. We have a massive trade deficit with China, a deficit we must find a way, quickly, to balance. A strong and smart America is an America that will find a better friend in China. We can both benefit or we can both go our separate ways."

In conclusion, Trump said: "We must make America respected again. And we must make America great again. If we do that, perhaps this century can be the most peaceful and prosperous the world has ever known.

Walid Phares, one of Trump's foreign policy advisers, previously warned the speech will be used to present a more expected presidential personality for Trump rather than the brass, outspoken persona he's known for. He added there won't be any specifics on any his policies, such as the much talked about wall across the Mexican border or how he plans to fight Isis.

"There will be no details in this speech," Phares said, "He's not going to say 'we're going to send three brigades to do the job.' No. He's going to confirm the principle that Isis should be destroyed so that the other political settlements can work."

Lanhee Chen, 2012 republican nominee Mitt Romney's chief policy adviser, added the speech was part of a "normalisation effort, or the mainstreaming" of Trump.