Prime Minister Lee Hsien Loong yesterday offered to host Pakatan Harapan (PH) de facto leader Anwar Ibrahim at an institute or think-tank in Singapore for a while.

And Datuk Seri Anwar has said he would consider it, PM Lee told Singapore reporters.

Mr Anwar and his wife, Datuk Seri Wan Azizah Wan Ismail, who is Deputy Prime Minister and Minister of Women and Family Development, called on PM Lee and Mrs Lee at the Marriott Hotel in Putrajaya yesterday afternoon, following PM Lee's call on Prime Minister Mahathir Mohamad.

"Mr Anwar is an old friend," PM Lee said in a Facebook post. "It has been more than 20 years since I last met him, back when we were both DPMs. It was good to catch up with him and Dr Wan Azizah again."

PM Lee was deputy prime minister from 1990 to 2004, and Mr Anwar from 1993 to 1998. But Mr Anwar was sacked from Cabinet in 1998 by Tun Dr Mahathir and later charged with abuse of power and sodomy, which he maintains was politically motivated.

After PH's electoral victory, Malaysia's King, Sultan Muhammad V, granted Mr Anwar a full pardon last Wednesday. Dr Mahathir has also promised to step down as prime minister in two years' time to make way for Mr Anwar.

But Mr Anwar has said he will not serve in the new government for now, as he needs "time and space" to rest with his family, and to travel abroad to fulfil teaching and speaking engagements.

PM Lee told reporters: "If he wants time to reflect, to write, perhaps to detach himself a little bit for a while, we welcome him to Singapore. Come to one of our institutes and write a book. He said he would consider that."

Mr Anwar told reporters separately that it was "a real pleasure" to meet PM Lee after all this while.

"Essentially, we believe in stronger bilateral relations with Singapore. That's the view PM Mahathir also stressed," he said.

Dr Wan Azizah added that it was a very good meeting, saying: "We so want to increase and have better bilateral relations, as neighbours and in the region."

PM Lee told Singapore reporters that both he and Mr Anwar used to exchange visits, and that their last visit was in 1995, when Mr Lee was in Kuala Lumpur and Penang, Mr Anwar's home state.

"We had a general conversation on how he saw developments in Malaysia, his views of what has been happening and what his plans were," PM Lee said. "The main thing was to re-establish the personal link I had with him."