DAVAO • Philippine President Rodrigo Duterte said he may turn down an invitation by President Donald Trump to visit the US.

Mr Duterte, who has loosened the Philippines' long alliance with the US while strengthening ties with China and Russia, said he could not commit to visiting Mr Trump because of a busy schedule that included a trip to Moscow.

"I am tied up. I cannot make any definite promise. I am supposed to go to Russia, I am supposed to go to Israel," he told reporters yesterday after visiting three Chinese warships. Mr Trump issued the invitation in what the White House called a "very friendly" phone conversation with Mr Duterte last Saturday.

Even though no firm date has yet been proposed for the trip, Mr Duterte expressed concerns about not being able to fit in a visit to Mr Trump. Nevertheless, he said relations with the US were improving under Mr Trump, whose predecessor Barack Obama had criticised him for his anti-drug war that has claimed thousands of lives.

Mr Duterte said his efforts to loosen the alliance were only a response to the drug war criticism.

"It was not a distancing (of relations) but it was rather a rift between me and the (US) State Department and Mr Obama, who spoke openly against me," he said. "Things have changed, there is a new leadership. He wants to make friends, he says we are friends so why should we pick a fight?"

The White House defended Mr Trump after the invitation came under fire from human rights groups, saying Mr Duterte's cooperation was needed to rein in North Korea's nuclear and missile programmes.

"There is nothing right now facing this country and facing the region that is a bigger threat than what's happening in North Korea," White House chief of staff Reince Priebus told ABC. Besides Mr Duterte, Mr Trump also spoke to Singapore's Prime Minister Lee Hsien Loong and Thai Prime Minister Prayut Chan-o-cha to seek their support to counter North Korea. Both leaders also received an invitation to visit the White House.

REUTERS , AGENCE FRANCE-PRESSE