National champion Ngưng will take part in the men’s event aiming to set a personal best to close in on Olympic qualification.
The 26-year-old took part in the 2016 event and recorded a personal best of 1hr 23.29; a national record.
"I have only had one month to prepare for this event. My recent results have been between 1.30hr to 1.33hr, which is around the Southeast Asian (SEA) Games gold medal time," said Ngưng.
Last year’s winner, Daisuke Matsunaga of Japan, won in a time of 1:20.55. The runners-up were Fumitaka Oikawa (Japan) and Kim Hyunsub (South Korea), who were around one minute behind.
"I know my ability but I will try to catch up with them," said Ngưng who will not be competing at the SEA Games later this year as the walk has been axed from the competition.
Ngưng was one of two Vietnamese athletes who qualified for the Rio Olympics after recording 1:23.29 three years ago, but he is unsure about repeating the feat.
"It is harder for me as well as many other Vietnamese athletes as the International Association of Athletics Federations has just released new qualification standards.
To win a berth to Tokyo in 2020 a male walker must reach 1:21.00 while women must hit 1:31.00.
Phúc, who is Ngưng’s older sister, has returned to competition after having a baby.
The 28-year-old dominated the national and SEA Games tournaments for many years. She was also the first Vietnamese walker to compete at an Olympics in London in 2012 where she set a personal best and the national record of 1:33.36.
Phúc is a familiar face at the Asian Championships as she claimed a silver in 2013 and a bronze in 2012.
She was a three-time winner of the SEA Games from 2011-15.
At the Japanese tournament, Phúc will be against powerful rivals from China, Japan, South Korea and India.
Last year, Duan Dandan of China triumphed in a time of 1:35.12. — VNS