Franklin Graham has said Madonna should be "ashamed" of herself for using her platform to threaten President Donald Trump and urged United States citizens to "pull it together as a nation" - even if they don't like the country's new leader. 

The 64-year-old evangelist made his comments on Facebook after the pop singer conducted a profanity-laced speech at the protest rally in Washington, D.C. Saturday, in which she said she felt "angry" and "outraged" over Trump becoming the country's 45th president.

"I'm angry. Yes, I'm outraged. Yes, I have thought an awful lot about blowing up the White House," Madonna said. "But I know that this won't change anything. We cannot fall into despair."

Graham, the leader of the Billy Graham Evangelistic Association and Samaritan's Purse, criticized the singer for her comments, which he called a "direct threat to the President of the United States and might've landed anyone else in jail."

"She should be ashamed," he continued. "The vulgarity in her program was terrible, but this is crossing another line and it's wrong."

According to Breitbart, a spokesman for the Secret Service reportedly told The Gateway Pundit that the agency was "aware" of the singer's comments and would launch an investigation, though the final decision on whether to prosecute would be made by the U.S. Attorney's office.

Graham said, "I hope that the Secret Service does take action to let her know how serious this really is. We certainly don't need those in the spotlight encouraging violence, we need to pull together as a nation. It's a new day. With God's help and mercy we can make changes for the better."

Madonna also performed her songs 'Express Yourself' and 'Human Nature' at the Women's March on Washington, DC on Saturday, and told demonstrators that the newly-inaugurated Presiden could "suck a d***".

The singer's behavior was criticized by a number of political leaders, including White House chief of staff Reince Priebus, who told Fox News: "One of the singers said she wanted to blow up the White House. I mean, can you imagine saying that about President Obama?"

Following backlash, Madonna took to Instagram to claim her remarks were taken "wildly out of context".

"I am not a violent person, I do not promote violence and it's important people hear and understand my speech in its entirety rather than one phrase," she posted. "I spoke in metaphor and I shared two ways of looking at things - one was to be hopeful, and one was to feel anger and outrage, which I have personally felt. However, I know that acting out of anger doesn't solve anything. And the only way to change things for the better is to do it with love."

Graham was among six religious leaders - including Paula White and Samuel Rodriguez - who offered prayers and Bible readings at the inauguration ceremony over the weekend.

Before reading 1rst Timothy 2 following Trump's speech, Graham stated, "Mr. President in the Bible rain is a sign of God's blessing, and it started to rain when you came to the platform. It's my prayer that God will bless you, your family, your administration, and may He bless America."