"We kept the senate despite having twice as many seats to defend as the Democrats. We are very proud of what has happened there."
He said the Democrats had spent "hundreds of millions of dollars against us".
Trump also railed against the count going on in the remaining battleground states, complaining that the election apparatus was run by Democrats.
He also said pollsters were wildly wrong with Ohio, picking Biden, which Trump eventually won.
He said the Republicans were winning many races until votes started to be whittled away.
He claimed Republican witnesses were not able to watch some of the vote counts and said: "There is tremendous amount of litigation due to how unfair this process is."
Trump claimed the count had "destroyed our system" and labelled it "corrupt".
"Our goal is to defend the integrity of the election," he said.
Trump thanked those who had supported him, saying "I have never seen such love and spirit".
He said there was "no question" some involved with tallying votes were involved in "fraud", claiming: "There is paper on the windows so you can't see in."
In America, NBC cut away from his speech.
Trump went on to call for "honest and transparency" and said the election voting issue could end up at the "highest court in the land".
Trump stressed he said pre-election that mail-in votes would be a "disaster".
"It will hopefully be cleared up, hopefully soon, but it will probably go through a legal process. There have been a lot of shenanigans and we can't stand for that as a country."
Meanwhile, his opponent Joe Biden has ''no doubt" he will win the election and is telling his supporters to stay calm as votes continue to be counted.
Biden delivered brief remarks at a theatre in downtown Wilmington, Delaware.
He said it was "the will of the voters — no one, not anyone else — who chooses the president of the United States of America".
That message is in stark contrast to Trump whose campaign has pursued legal efforts to halt the vote counting in some states and is seeking a recount in Wisconsin.
Two days after voting day, an uneasy United States is still waiting to hear who will be its next president.
Biden is pushing closer to the 270 Electoral College votes needed for victory, with the decision resting on six key states.
The President spent the day at the White House, working the phones and escalating efforts to sow doubt about the outcome of the race. In a series of tweets, he pushed baseless allegations of electoral misconduct and said the ongoing vote count of ballots submitted before and on Election Day should cease.
