Malacanang said on Tuesday foreign human rights experts who have negative conclusions about the Duterte administration's war on drugs would not be allowed to enter the country despite seeking permission from Vice President Leni Robredo, the government's drug czar.

In a press briefing, Presidential Spokesperson Salvador Panelo cited Phelim Kine, former deputy director for Asia of the New York-based Human Rights Watch, who would be covered by the ban.

He said he agreed with the statement of Foreign Affairs Secretary Teodoro Locsin Jr. that Kine would not be allowed to enter the Philippines "because he has already reached a conclusion - this is a murderous country and then he said President (Rodrigo) Duterte should be arrested."

Kine, in his tweet to Robredo, said he was ready to come to the Philippines to help the vice president to end the "murderous" drug war.

Kine recommended the arrest of Duterte and his henchmen "for inciting & instigating mass murder."

While the Palace earlier said that Robredo would be given all that she needs in the campaign against illegal drugs, Panelo, however, said it was a different matter if foreigners who want to investigate the war on drugs have their own conclusion.

Their entry would be an intrusion of the country's sovereignty, said Panelo, also chief presidential legal counsel.

"Anybody who gives a conclusion that there have been killings, murders without justification, they will have a problem," he said.

Meanwhile, on Robredo's call for higher budget in the campaign against illegal drugs, quoting Duterte, he said it would be better to ask Congress, which is deliberating the proposed budget for next year. Celerina Monte/DMS