Donald Trump predicts massive win for Republicans in November 3 polls

US President Donald Trump has predicted a massive win for the Republicans in the November 3 elections, saying the margin would be much bigger than what the party had received four years ago.

Speaking at four different rallies in the battleground State of Pennsylvania on Saturday, Trump said his administration has made tremendous accomplishments in the last four years under his presidency.

"It's going to be a very interesting Tuesday. You have a big red wave that has formed. Nobody's ever seen anything like this," Trump told the cheering crowd.

In almost identical speeches, Trump reflected upon the accomplishments of his administration in the first term, while made allegations of massive corruption by the family of his Democratic challenger Joe Biden.

The president also accused the Democrats of taking the country on a path of socialism and raising taxes if Biden wins the election.

The president, who is trailing behind Biden in battle ground States including Pennsylvania, said that he will win these States and his margin of victory would be greater than that in 2016.

A wave is forming, he said.

"They see it forming on all sides and there's not a thing they can do about it. This is the state where the story of American independence began," Trump said at a place in Pennsylvania where the first president George Washington plotted his trip across the Delaware River during the American Revolution.

"It's the state where the American Constitution was signed. Three days from now, this is the state that will save the American Dream. On November 3, we're going to win Pennsylvania. We're going to win four more years in that very beautiful White House," he said.

Trump, 74, said he did excellent job in the areas of defence.

"In 2016, Pennsylvania voted against this failed establishment. You voted for an outsider who is finally putting America first," he said as he listed some of his key achievements from military to jobs and peace in the Middle East.

"Over these last four years we've been building the strongest and most secure middle class in human history. We've built the most powerful military in the world by far," he said.

Trump during his Saturday rallies called Biden low with energy.

"I do what's right for America. I have made a lot of enemies in Washington. I wear their opposition like a badge of honour, he said.

In his speech, the president continued to slam his Democratic opponent quite calling him as one with low energy or Sleepy Joe.

"He works for them and not for you. I work for you," Trump said.

"Biden's plan will destroy America and my plan will destroy the virus and make it greater than it's ever been," he said.

The president also urged his supporters to be very, very careful" and "vigilant" this election.