He takes over from George Osborne, who has resigned from the government.
"The fact that we've moved quickly to resolve the question of the leadership of the Conservative party and get a new Prime Minister installed I think will help to restore business and consumer confidence".
The Chancellor said the new Cabinet had not made any decisions about changing United Kingdom tax laws.
Barclays and Credit Suisse have both this week predicted that the Brexit vote will tip the United Kingdom into recession and Bank of England Governor Mark Carney made a similar prediction prior to the vote.
"Markets do need signals of reassurance, they need to know that we will do whatever is necessary to keep the economy on track", he told ITV News.
He told BBC News he would be making some "carefully considered decisions over the summer" about the economy.
"I'm not going to set out what my plans will be here on TV this morning", he said. The rates may be cut be from 0.5 percent to 0.25 percent to boost the economy in the wake of the Brexit vote.
Hammond added that during Brexit negotiations with the EU, the government needed "to ensure access to the European Union single market" for London's financial services.
The timing for deficit reduction had to be reconsidered, Hammond said, and ratifying a new deal with the European Union would have to be agreed by 27 national parliaments so would take some time. Hammond said: "After that comment was made, Richard Madeley contacted me to make a very important correction".
He continued: "If there is one thing that is damaging our economy today it is uncertainty ..." "We've got to reduce the deficit further", he said.
After Hammond, other figures including former London mayor Boris Johnson - the "Leave" campaign figurehead in the referendum - Energy Secretary Amber Rudd and Defence Secretary Michael Fallon were seen walking into 10 Downing Street.
In April, Johnson suggested that U.S. President Barack Obama had an "ancestral dislike" of Britain because he is part-Kenyan. "Frankly, this is a relationship that goes beyond personalities", he said.
First, negotiating a divorce with the European Union will take up to two years. It is said that the Queen has come to love the Commonwealth, partly because it supplies her with regular cheering crowds of flag-waving piccaninnies; and one can imagine that Blair, twice victor overseas but enmired at home, is similarly seduced by foreign politeness. "Lastly, one could also argue that is better to have a key member of the Leave campaign in the cabinet, rather than sniping from the sidelines". In a statement delivered in Downing Street after taking office on Wednesday, May said she would focus any tax cuts on the lower paid.
Mr Hammond said he thought that Mr Johnson would be good in the role and that Mrs May had put together a team that would work successfully.