The United States may need a big win against Portugal at the Women's World Cup on Tuesday to top Group E, but coach Vlatko Andonovski has warned his team to focus on simply securing their place in the last 16.

The holders and favourites to win an unprecedented third consecutive World Cup have not yet hit peak form, beating minnows Vietnam 3-0 in their opening game at the tournament and then drawing 1-1 with the Netherlands in a repeat of the 2019 final.

Level on four points with the Dutch at the top of their group, a big win for the Netherlands against a weak Vietnam could relegate the Americans to second place.

But the priority for the record four-time world champions is to avoid defeat against tournament debutants Portugal, who have three points, and prevent a shock first-round exit.

"The most important thing obviously is getting in the knockout stage first and foremost and that is our main focus right now," Andonovski said at Eden Park in Auckland on Monday.

"We don't want to look two, three or four steps forward. If we start thinking too far ahead, our chance may never come."

Portugal beat Vietnam 2-0 last time out, having previously competed well in a 1-0 defeat against the Netherlands in Dunedin.

They also held European champions England to a goalless draw in a friendly just before the tournament.

"It will absolutely not be a walk in the park," Andonovski warned.

"They are a great team, they are very well coached, they are disciplined, organised. We are so focused on this game and making sure we get a favourable result."

Lavelle hint

The US coach also hinted that Rose Lavelle could have a greater role to play after appearing as a substitute against the Netherlands.

Lavelle, who was struggling for fitness before the World Cup, replaced Savannah DeMelo at half-time against the Dutch with her team trailing, and duly set up the equaliser for captain Lindsey Horan.

"Rose is one of the best players in the world and not having her for the full 90 minutes in the first two games obviously impacted the team because coming into this World Cup she was pencilled in as a starter a long time ago," Andonovski said.

"She makes things happen on the field. We are very happy that her minutes have been increasing and we are looking forward to seeing more of her on the field."

Andonovski knows all about Portugal's threat as he is a friend of their coach Francisco Neto.

"Francisco is a great guy and we have a great relationship. We have spent a lot of time together, I think he is an incredible coach but business is business," Andonovski said.

Portugal are ranked 21st in the world and a win would not just send them through to the last 16 -- it would send shockwaves through the sport.

"We know that the US needs to win and needs a lot of goals to come first but we have our goals in the World Cup and we want to continue in this competition," said Neto.

"We are expecting to see the best USA in this World Cup and we are preparing our team to be the best Portugal for tomorrow."