RIO DE JANEIRO, April 9 (Xinhua) -- Brazilian President Michel Temer said Monday that the country is undergoing a "difficult time" politically, but called on the people to "keep carrying on" and respect the Constitution.

Speaking in Rio de Janeiro at the national development bank, Temer avoided directly referencing former president Luiz Inacio Lula da Silva, who was arrested on Saturday to begin a 12 year and one month prison sentence for corruption, sparking protests nationwide.

"We need to know that we are coming out of a difficult time for the country, we continue seeing a difficult time politically, but we must keep carrying on," said Temer.

He added that "carrying on means... carrying out the Constitution... which is what gives stability to the country."

"We can only have organization when there is a controlled and strict following of the law. When somebody thinks they need not abide by the law, they sow disorganization among society."

Lula turned himself in on Saturday to federal police after an arrest warrant was issued against him on Thursday by Sergio Moro, the judge overseeing Operation Lava Jato.

On Monday, Lula's defense team said they would continue to fight to overturn his sentence. One of his lawyers, Cristiano Zanin, told the press that "from what we understand, there is no legal reason for him being a prisoner and we will take every avenue for this imprisonment to be revoked."

The team may also be planning to ask that Lula be moved from prison in Curitiba, the capital of the southern state of Parana, to the state of Sao Paulo, where Lula lived with his family. "We will analyze this but we cannot reveal the defense strategies," Zanin commented.