TAIPEI (Reuters) -Taiwan's trade negotiations with the United States are still underway and will be submitted to parliament for review once finalized, and must remain confidential in the meantime, deputy chief trade negotiator Yen Hui-hsin said on Monday.

Yen's comments to Parliament came after Taiwan's President Lai Ching-te said on Friday the 20% U.S. tariff is "temporary" and the government will continue to strive for reasonable tariff rates and complete the final stage of negotiations.

During a cross-party consultation on the issue, opposition parties, the Kuomintang (KMT) and Taiwan People's Party (TPP), voiced concerns over the cabinet's refusal to disclose details of the negotiations.

"This confidentiality agreement is being handled in accordance with Article 12," Yen said, referencing a provision of Taiwan's treaty laws.

Yen defended maintaining confidentiality, citing U.S. requirements. "In tariff negotiations, the U.S. mandates confidentiality agreements before any consensus is reached to avoid unnecessary disruptions," she said. "Because of the diplomatic considerations involved, this has not been submitted to the Legislative Yuan (the parliament) for review."

The agreements are designed to protect sensitive information and regulate information exchange, prohibiting unauthorized sharing of negotiation materials, she said.