British MP Paul Murphy held talks with Sri Lankan officials handling the Norwegian-backed peace process, officials said, adding he planned to meet with Tamil Tiger rebels before departing Thursday.
"He is also meeting the Sri Lanka Monitoring Mission (SLMM)," a British High Commission (embassy) official said.
Government officials said President Mahinda Rajapakse was hosting Murphy at a dinner and would discuss the collapsing peace process. Murphy will also separately meet with the government's four-member peace negotiating team.
Murphy arrived in the island a day after the United Nations accused government forces of forcibly recruiting child soldiers on behalf of "the Karuna group", an allied paramilitary force fighting Tamil Tiger rebels.
The special advisor to the UN Representative for Children and Armed Conflict, Allan Rock, told reporters that government soldiers had rounded up Tamil children to be recruited by the Karuna group.
The charge came on top of international condemnation of the killing of a large number of Tamil civilians during an artillery exchange between troops and the Tigers in the east last week.
Shells fired by security forces hit a refugee centre and killed up to 65 people. Rajapakse expressed regret over the killings and ordered an investigation.
Rock, who visited the area shortly after the military shelling, said civilians were living in fear and children were severely affected.
"People are even afraid to go to the bathroom, fearing that they will be hit by shells," he said at the end of a 10-day mission. "People did not want us to leave," he said. "The situation is beyond desperate."
"Wherever I travelled, I saw with my own eyes that systems meant to safeguard children's rights are either deteriorating or absent," he added.
"There is an urgent need for an independent monitoring capacity to ensure children affected by the conflict are protected."
Rock did not elaborate on the proposed mechanism, but said he would report back to the Security Council on his findings.
The allegations over child recruitment marks the first time the UN has levelled such a charge against Colombo.
The Tamil Tigers have long been under fire for using child soldiers in their separatist war.
The army said the UN allegations were "completely misleading". However, Rock said the president, who is army commander-in-chief, had pledged an "immediate" investigation and to punish anyone found guilty.
"The complicity of the security forces with the Karuna group is common knowledge. It corrodes respect for the rule of law and creates space for more LTTE abductions of children," he said.
Diplomats said the assassination of a moderate Tamil legislator on Friday has also damaged Sri Lanka's human rights record and drawn condemnation from the island's main financial backers.
Rights violations have been on the rise as fighting between troops and Tamil Tiger rebels has escalated despite a truce in place since February 2002.
Over 3,300 people have been killed in the new cycle of violence in the past year, according to official figures. Sri Lanka's Tamil separatist conflict has claimed over 60,000 lives since 1972.

Copyright AFP (Agence France-Presse), 2006