Kenya sent troops into southern Somalia a little more than a week ago to chase after al-Shabab militants, who Kenya blames for a series of cross-border kidnappings.
On Monday, President Sharif said only African Union troops can operate legally in Somalia, and cautioned against Kenya doing anything to harm the two countries' relations.
Deputy Speaker Moallim says Kenya has the right to defend itself. He also said Kenya's intervention is aimed at curtailing the danger presented by al-Shabab, and stopping the huge flow of Somali refugees into Kenya.
More than 450,000 Somali refugees are living at a huge refugee complex in Dadaab, not far from the Kenya-Somalia border.
Kenyan forces have launched airstrikes in Somalia and advanced close to al-Shabab-controlled towns but have yet to fight a major ground battle with the militant group.
On Sunday, a Kenyan army spokesman said the French navy had bombed the al-Shabab-ruled city of Kismayo but France denied the report.
Al-Shabab is fighting to topple the U.N.-backed Somali government and set up an Islamic state in Somalia. The group has lost ground to Somali government and African Union troops in recent months but still controls considerable territory in southern and central Somalia.
Some information for this report was provided by AP, AFP and Reuters.