Republican presidential frontrunner Donald Trump just made another controversial remark, this time directed against his partymates in Congress.

In an interview on CBS, the outspoken business tycoon said his party "never wins" in the legislative battlefield because most Republican lawmakers take the side of US President Barack Obama, who is a Democrat.

"Here's the problem: You cannot win when you have a group of 25 or 30 percent on this side, and you have a group of 70 percent on this side," he said in the interview on Sunday, referring to congressional Republicans.

Trump also pointed out that Republican lawmakers can exert greater pressure on Obama only if they will work together.

"It's so sad. Because if they were really going to fight, and if they took that 30 percent stance, assuming they wanted to really make changes and do it right, and cut the budget, cut the deficit, and do things that they should be doing, if they took that group and if everybody was unified, Obama would fold," the Republican presidential aspirant said.

"But there's no reason for him to ever fold, because he knows that a big proportion, a vast majority of the Republicans are on his side," he added.

In the same interview, Trump also called on Arab states to work together to create a safe zone for Syrian refugees.

"The countries should all get together, including the Gulf States who have nothing but money. They should all get together, and they should take a big swath of land in Syria, and they should do a safe zone for people, so they can have a safe place where they could live," the Republican presidential hopeful said.

"I've been watching this migration, and I see the people. They're mostly men, and they're strong men. These are physically young, strong men. They look like prime time soldiers. It's probably not true. Where are the women? You see some women, you see some children, but for the most part, I'm looking at these strong men. So you ask two things. Number one, why aren't they fighting for their country? Number two, I don't want these people coming over here," he added.

He also once again pointed out the danger of allowing refugees in the US.

"Two hundred thousand people? This could be the greatest Trojan horse. This could make the Trojan horse look like peanuts if these people turned out to be a lot of ISIS," Trump said.