Many eyes are now fixed on what will come out of the first face-to-face meeting between Mr Brash and Mr Tough. Will there be a clash of personalities?
US President Donald Trump, who has been in office little more than 10 weeks, will meet on Thursday (April 6) and Friday his Chinese counterpart Xi Jinping, who has honed his US strategy since assuming the Chinese leadership in 2013.
Chinese officials are mindful of the pitfalls if Mr Trump veers off-script, while US officials are concerned Mr Trump may not come to the table as prepared as Mr Xi.
So how will US-China ties pan out? The following signs may offer some clues:
1. Will there be a proper first handshake?

Mr Trump's forceful, arm-jerking handshake has been read by body language experts as a sign of his desire to dominate and show that he is the boss, the South China Morning Post (SCMP) reported.
"And patting a hand after you have grabbed and jerked it and not let it go, indicates a desire to further bully the receiver, symbolically saying, with each pat: 'I hit you. I hit you,'" US body language coach Patti Wood said, analysing the US leader's handshake.
Japanese Prime Minister Shinzo Abe found himself in a long, uncomfortable handshake at the White House in February.
Mr Trump appeared to snub German Chancellor Angela Merkel's offer of a handshake during their meeting in March.

But Mr Trump is certainly not the only leader who seeks to send a message through his handshakes.
Remember that empty expression Mr Xi put on when he shook hands with Mr Abe at the Asia-Pacific Economic Cooperation (Apec) summit held in China in November 2014?
That was his blandest look seen throughout the summit.
That handshake marked, however, a turning point in ties between China and Japan, following renewed tensions over the East China Sea islands which both countries claim as their own - The Japanese call the islands Senkaku, and the Chinese name them Diaoyu.
2. No golf, and likely no beer. So, what will gel them?

There will be no golf diplomacy, unlike Mr Abe's visit to Mr Trump's Mar-a-Lago resort in Florida in February.
Mr Xi's Chinese Communist Party associates golf with shady dealings and has sought to stop officials from playing it as part of Mr Xi's battle against widespread corruption.
There will also be no Happy Hour as Mr Xi and Mr Trump are unlikely to share a jug of beer. While Mr Xi managed to share an ale with former British prime minister David Cameron in 2015, the gesture will not work for Mr Trump, who is reportedly a teetotaller since the death of his brother from an alcohol-related illness in 1981 at the age of 43.
Mr Leow Chee Seng, a professor of non-verbal communication and behaviour at the Human Behaviour Academy in Malaysia, told the SCMP that Mr Xi should offer tea as a gift and the two leaders should minimise the risk of social gaffes by limiting their social activity.
3. When a former model meets a former singer
A popular former singing star in the People's Liberation Army, Chinese first lady Peng Liyuan will be at President Xi's side as he meets his US counterpart.

While details of her programme in Florida have been largely kept under wraps, Ms Peng and Mr Xi will dine with Mr Trump and his wife Melania on Thursday.
Ms Peng has become a regular feature of China's global outreach since her husband took the reins of state in 2013.
The state-run China Daily newspaper had previously compared Ms Peng with former US First Lady Michelle Obama, calling them both symbols of glamour who "stand uneclipsed by their more powerful husbands". Ms Peng and Mrs Obama in September 2015 unveiled the name of a baby panda - Bei Bei - at the Smithsonian National Zoo in Washington DC, when then President Obama and Mr Xi met at the White House.
Former model Melania has been mostly absent since her husband took office on Jan 20, spending much of her time in New York, caring for the couple's 11-year-old son Barron.

But she hosted a White House luncheon for International Women's Day last month. Last week she attended a White House event for senators and their spouses. She has also hired a communications director, Ms Stephanie Grisham.
It will be interesting to see if there is chemistry between Ms Peng and Mrs Trump.
4. Another Chinese song by Ivanka's daughter?

In February, when many wondered why Mr Trump did not follow precedent and send a personal Chinese New Year greeting to the Chinese community, Ms Ivanka Trump made a surprise visit to the Chinese embassy in Washington with her five-year-old daughter Arabella Kushner.
Ms Trump also posted a video on Instagram of Arabella singing a new year song in Mandarin as she swayed, holding a red Chinese lion dance puppet on strings, the South China Morning Post reported.
She has often shared videos of Arabella speaking Chinese and celebrating Chinese culture. Arabella has reportedly been learning the language since she was 18 months old.
So perhaps Arabella could sing a Chinese song with Chinese First Lady Peng Liyuan this time round? Sing song diplomacy might just do wonders to bilateral ties, following the ping pong diplomacy of the early 1970s.
Sources: South China Morning Post, Reuters, NYTimes, Guardian