YANGON: Myanmar pro-democracy leader Aung San Suu Kyi is in better health after receiving medical attention but her personal doctor remains in detention, her political party said Tuesday.

The 63-year-old was placed on an intravenous drip again on Monday by her doctor's assistant and can now eat, while her blood pressure has returned to normal, said Nyan Win, spokesman for her National League for Democracy.

"Her health is improved. There is no need to worry for her health as the medical assistant gave her the necessary medical treatment," Nyan Win told AFP.

But he said that the Nobel Peace laureate was suffering from leg cramps and would benefit from a full check-up by her personal doctor Tin Myo Win, who was detained by police on Thursday on unspecified charges.

"It will be a long-term process. She needs her personal doctor," he said.

The opposition icon has spent most of the last 19 years in virtual isolation at her lakeside home in the main city of Yangon, living with her two maids and permitted occasional visits from her lawyer and doctor.

Tin Myo Win was arrested a day after Myanmar authorities arrested a US national who had swum across a lake to Aung San Suu Kyi's off-limits compound and spent two days there.

Her doctor's assistant, Pyone Moe Ei, visited Aung San Suu Kyi last Friday when she found her with high blood pressure, unable to eat and dehydrated.

Pyone Moe Ei was refused a second visit on Sunday but allowed to return on Monday to renew the intravenous drip.

Aung San Suu Kyi's latest period of detention expires at the end of May and authorities have not said if they will extend her sentence.

The US government on Monday demanded that the junta grant "immediate" access for Aung San Suu Kyi to see her doctor, expressing fears for her condition.

The NLD won a landslide victory in elections in 1990 but the military refused to let the party assume office. Myanmar has been ruled by the military since 1962.