Hillary Clinton and Donald Trump have cast their votes in the US Presidential election and now wait for the country to make its choice.

The Democratic nominee and her husband, former president Bill Clinton, voted at an elementary school near their home in suburban New York before greeting supporters waiting for her outside.

"It is the most humbling feeling," she said of voting for herself for president. "I know how much responsibility goes with this."

Republican presidential nominee Donald Trump also cast his ballot in New York City.

Protesters were escorted out as they shouted anti-Trump slogans at a polling station the Republican candidate was due to vote at. Photo: Reuters/Darren Ornitz

He arrived at a Manhattan polling place with wife Melania, daughter Ivanka and her family. Trump paused to wave to supporters who had gathered outside. A crowd booed at him.

Inside, he bought a bag of cookies from kids having a bake sale and greeted supporters before casting his ballot.

The New York businessman began Election Day with a ritual call to the "Fox & Friends" morning news show. "I'm a little bit superstitious," he said. "I've won many primaries speaking to you first in the morning."

Prior to Trump's arrival at the New York polling station, security forcibly removed two topless women protesters yelling anti-Trump slogans. Among the slogans the women had daubed on their bodies was one that read 'OlO FEMEN USA'.

Femen is a feminist protest group which describes itself as an "international women’s movement of brave topless female activists painted with the slogans and crowned with flowers."

A Reuters/Ipsos States of the Nation poll gave Democratic rival Hillary Clinton a 90 percent chance of defeating Trump and said she was on track to win 303 electoral college votes out of 270 needed, to Trump's 235.  

In a buoyant mood, Mrs Clinton greeted voters who cried out "we love you," smiling back: "I love you all, too ... absolutely."

Democratic Party campaign aides projected confidence in the final moments. They said they felt good about Nevada, where they said support for Mrs Clinton in early voting was strong. They were encouraged by the strong Latino turnout in Florida and felt they took a strong lead in Michigan and Pennsylvania into election day, when the bulk of votes are cast in those states. 

Topless protesters showed up at the polling station Trump subsequently voted at. Photo: Reuters/Darren Ornitz