Northern Ireland's Deputy First Minister Emma Little-Pengelly has said the trip to Washington DC for St Patrick's Day has been "an incredibly fruitful one".
She said she has had several "significant conversations" with US President Donald Trump and has engaged with the new UK ambassador to the US, Peter Mandelson.
Northern Ireland's First Minister Michelle O'Neill said last month that she would not attend the St Patrick's Day celebrations in Washington.
Sinn Féin announced that the party would not travel to the US as part of "a principled stance against the threat of mass expulsion of the Palestinian people from Gaza".
Asked whether the US engagements had been limited due to the absence of Ms O'Neill, Ms Little-Pengelly said she thinks it "shows a confidence in our Executive".
Speaking at the NI Bureau breakfast in Washington DC, she said: "I think it demonstrates that the Executive is actually working well together.
"I believe I'm a very strong voice for Northern Ireland. I'm not shy about putting forward our case and making sure that we do get into those rooms, and we are saying everything that is fantastic about our wonderful place we call home."
Ms Little-Pengelly said she has also spoken with the two US nominees to become ambassadors to the UK and Ireland.
"These are really key conversations because, of course, these are the people, the policymakers, the influencers, that are key to speak up for Northern Ireland, particularly when dealing with tricky issues," she said.
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She said it is important that Northern Ireland does not become "collateral damage" in any trade war between the US and EU, adding that they were in a "tricky situation" with regards trade that she intended to highlight with ambassadors.
Post-Brexit rules, set out in the Windsor Framework, aligns Northern Ireland trade processes with EU customs arrangements while remaining part of the UK's customs union.
President Trump is threatening to impose tariffs on the EU, signalling a 200% tariff on alcoholic drinks from the EU, to balance what he has called a "massive" trade deficit with the bloc.
Asked about the threat of tariffs and how it could affect Northern Ireland, Ms Little-Pengelly said: "The key issue for me is that we don't become that collateral damage, and we need do everything that we can to influence that.
"If we are caught up in this, in truth that it is going to be, in my view, the collateral. It is not going to be the aim of this.
"So, of course, my role here is to make sure I'm speaking up for Northern Ireland and trying to ensure as many people as possible are aware of the dangers of this.
"A trade deal with the US would be and would have, as an aspect of that, some form of tariff reduction. So, of course it's important as well that Northern Ireland can benefit from that," she added.
Ms Little-Pengelly said it had been repeatedly raised with UK governments and prime ministers that Northern Ireland needed to benefit from future trade deals.
"There are ways to do this. This is not just a binary black-and-white situation where there is either tariffs in this area, or there's not," she said.
"There's always these sort of conditions and carve-outs around all of those. But we need the people in the room to be aware of the issue to make sure that that happens for Northern Ireland."
She said the investment environment has been "challenging" because of the global uncertainty and companies had waited to see the outcome of the US election.
"That uncertainty does continue, because people are not clear what America First as a policy will mean in terms of potential punitive measures," she said.
"There is money to invest, no doubt about that. People are waiting to have a little bit more certainty, but that is the opportunity for us to get in there and to make our case."
