UN chief Ban Ki-moon's top aide will arrive in Sri Lanka on Saturday to press for the safety of war-trapped civilians, a spokesman said, as Colombo looked set to bring the lengthy conflict to an end.
The visit by Ban's chief of staff Vijay Nambiar was due after the Sri Lankan government vowed Friday to finish off the Tamil Tigers within 48 hours, defying international calls for a truce.
"He's hoping to discuss the safety of civilians with the president (Mahinda Rajapakse) and several other key officials," UN spokesman Gordon Weiss said.
Tens of thousands of Tamil civilians are believed to be trapped inside a tiny patch of jungle still held by the rebels in the country's northeast. Hundreds have been reported killed in indiscriminate shelling over the past week.
The International Committee of the Red Cross, the only neutral group in the conflict zone, has said its staff are "witnessing an unimaginable humanitarian catastrophe."
Nambiar's trip for talks with the president would be his second in a month. He was here last month on a similar mission but failed to get agreement from the government for a pause in the fighting to allow civilians to escape the crossfire.
UN deputy spokeswoman Marie Okabe said in New York late Thursday that Ban was sending his deputy to press for protection of trapped civilians in the conflict and "help resolve the humanitarian situation."
Okabe added Ban was "seriously considering an invitation" from Colombo to visit the strife-torn Indian Ocean island nation "if it is going to save lives on the ground."
She said the UN chief spoke by telephone with President Rajapakse on Wednesday and reiterated his concern about the protection of civilians in the conflict zone.
Also Wednesday, the UN Security Council voiced "grave concern" at the "worsening humanitarian crisis" in Sri Lanka where an estimated 50,000 civilians may be trapped in fierce fighting between troops and the rebels.
Sri Lankan authorities hope to capture the remaining rebel territory by Sunday morning and end the offensive operations against the Tigers with their defeat after 37 years.