Trump hit with backlash after inviting Philippine Leader Rodrigo Duterte to the White House

President Trump is facing backlash after inviting the Philippines' controversial leader Rodrigo Duterte to the White House.

The president reportedly extended the invite to Duterte to the White House during phone call on Saturday which the two world leaders discussed rising tensions in North Korea.

The invitation reportedly surprised even those within his own administration.

According to the New York Times, at least two senior officials within the administration expected the State Department and the National Security Council to raise internal objections, having been "caught off guard" by the unexpected invitation.

Meanwhile, human rights groups have already spoken out.

"By essentially endorsing Duterte's murderous war on drugs, Trump is now morally complicit in future killings." John Sifton, of Human Rights Watch, said.

Senator Ben Cardin, the Ranking Member of the Senate Foreign Relations Committee, said he was "deeply disturbed" by the invitation in a statement published on Monday.

"This is a man who has boasted publically about killing his own citizens," the statement read. "The United States is unique in the world because our values – respect for human rights, respect for the rule of law -- are our interests. Ignoring human rights will not advance US interests in the Philippines or any place else."

Duterte, who became president of the Philippines last year, has been known for his blunt rhetoric and aggressive efforts to end what he considers to be a drug epidemic in the Philippines.

During his campaign he vowed that his presidency would be a "bloody one" and said he would pardon himself and other officers for murder and other human rights violations as needed in the war on drugs. Reports have emerged of "slaughter" on the streets in the months since he has taken office.

He even said he would kill his own child if he found out he or she had used drugs.

One human rights group estimates that Duterte's drug crackdown has resulted in the deaths of around 7,000 people.

The liberal group ThinkProgress argues that Trump's friendliness towards the Philippine president may have been influenced by a lucrative licensing deal of the Trump name on a new development in the capital city of Manila.

The White House has defended the invitation as an effort to combat against the threat of North Korea.