By Cordelia Lynch, US correspondent
Donald Trump's national security adviser John Bolton has told Sky News that America is "ready to go" with a US-UK trade deal.
In a UK exclusive, the former US ambassador to the UN said: "We are ready to go, we are ready to go."
"Trade minister Liam Fox would be welcome here; any member of the government would be welcome here, we can do these deals quickly. We are ready to go. We want to partner with a newly independent Britain."
Before joining the Trump administration, Mr Bolton expressed his support for Brexit. I asked him if he'd had a change of heart, after a week which has seen the UK teeter on the brink of a constitutional crisis.
"If I were a private citizen again I would have a lot of commentary on it," he said, "but I'll just say this: the president has been clear he wants a resolution to this issue that allows the United States and Britain to come to trade deals again.
"He sees huge opportunity if Britain's status can be resolved, and I think the point he has made that I would stress is, people of Britain have voted. Where is the political class going to give effect to that vote?"
But it is the crisis in Venezuela that is at the forefront of his mind. Mr Bolton has been ramping up his criticism on President Nicolas Maduro and helped rally international support for the opposition leader Juan Guaido.
He's turned to Twitter, echoing the approach of his boss to foreign policy, to try and apply pressure on Mr Maduro's regime.
In recent days, Sky News has witnessed children eating rubbish in Caracas and drinking sewage water.
But Mr Bolton, who has built a reputation as a straight talking foreign policy hawk, says the US is not ready to take military action.
"I don't think we are closer to military action," he said. "Although the president is very clear that all options are on the table. Remember that there are roughly 40,000 to 50,000 American citizens in Venezuela, so we are concerned for them as well."
Top military leaders are helping to keep Mr Maduro in power. But Mr Bolton says senior members are escaping in secret.
He said: "A substantial number of the families of military leaders have left the country. Some of them, are in Miami, some in Panama, some in Cuba, some in Spain."
He insisted that top military officials have confidence in his administration.
He and the president are hoping to get support from Brazilian President Jair Bolsonaro, dubbed the "Trump of the Tropics" who is visiting the White House today.
In echoes of Mr Trump, the outspoken leader has talked about putting Brazil first, draining the swap and fighting socialism.
He's courted plenty of controversy too, saying he'd rather his son die than be homosexual and once telling a female congresswoman he wouldn't rape her because she doesn't "deserve" it.
Mr Bolton said it wasn't the administration's job to deal with those statements and that the administration's focus is now on the strategic political and economic issues they can agree on. Mr Bolsonaro is the first overtly pro-American president to lead Brazil.
"I don't think it's for officials of our government to give movie reviews of the performance of the 192 other world leaders on the world stage," Mr Bolton said.
"Everybody says things that somebody else objects to. We're not in the literary criticism business.
"We make our views known on a lot of these issues, privately, we've got important government-to-government business to get on with, especially in the case of President Bolsonaro, who I think is prepared to see a profound change in the relationship with the US. We think that's all to the good."