Peiris was referring to Europol's Terrorist Situation and Trend Report this year which said the LTTE is still considered active and benefiting from support in countries with a significant diaspora.
The LTTE was banned as a terrorist outfit by the EU in 2007.
Peiris said he was happy that the EU delegation was able to see for themselves the progress made by the Sri Lankan government.
The parliamentarians for their part urged the government to conduct the September's provincial council election in the Tamil-dominated north in a civilian environment.
Sri Lanka has resisted international calls for de-escalation of the military presence citing national security imperatives.
The delegation also stressed the need for the full implementation of Sri Lanka's reconciliation commission (LLRC) recommendations in order to achieve comprehensive national reconciliation.
Most EU nations, along with India, had backed the two US-moved resolutions at the UN Human Rights Council which called for greater steps for rights accountability in Sri Lanka.