Up to 200 Kenyan soldiers were killed in an attack on their camp in Somalia by al-Shabab last month, Somali President Hassan Sheikh Mohamud said - although Kenya rejected the figure.
On January 15, dozens of heavily-armed al-Shabab fighters assaulted a Kenyan-run military base for African Union peacekeepers in the southern Somali town of El-Ade, not far from the Kenyan border.
"When about 200 soldiers who came to help your country are killed in one morning, it is not something trivial," Mohamud told Somali Cable TV, a privately owned station. The interview was posted on YouTube on Thursday.
"We have been winning for years and months but that El-Ade battle, we were defeated. Yes, in war, sometimes something that you do not like happens to you," the Somali president added.
Kenyan authorities have refused to give a death toll following the attack, which targeted troops working under the African Union Mission in Somalia (AMISOM).
But Kenya Defence Forces spokesman, Colonel David Obonyo, denied the number given by the Somali president and questioned the source of the information.
"It is not true. This information never came from us or anyone in the government of Kenya," he told the Reuters news agency on Thursday.
Series of attacks
Newspaper pictures of coffins draped with Kenyan flags bringing back dead soldiers after last month's attack increased the disquiet from ordinary Kenyans and the opposition alike over Kenya's continued presence in Somalia.
Al-Shabab later distributed photos purporting to show the bodies of dozens of Kenyan soldiers, many apparently shot in the head.
Kenya sent soldiers into Somalia in 2011 after raids in the border region and kidnappings that threatened the tourism industry in the region's biggest economy and wider regional destabilisation. It later joined the AMISOM operation.
Al-Shabab's attacks in Kenya have included a raid by gunmen on the upscale Westgate shopping mall in 2013 and a university in Garissa in 2015. Hundreds of people have been killed in al-Shabab attacks in the past two years.
The group has been driven out of major strongholds in Somalia by AMISOM and Somali army offensives, but it still controls some rural areas and often launches guerrilla-style assaults and bomb attacks.
Al-Shabab, which has links to al-Qaeda and seeks to overthrow Somalia's Western-backed government, initially said it had killed more than 100 soldiers in the attack.
The group, which is also seeking to drive the AU force out of Somalia, often says its attacks against Kenyan targets are retaliation for its participation in AMISOM, which also includes Uganda and Burundi.
The release of President Mohamud's interview came as at least three people were killed and nine wounded on Thursday when al-Shabab fired mortars at the presidential palace in Somalia's capital Mogadishu, health officials said.
The wounded, including three children, were brought to the Dar-ul Shifa hospital from the Ago dhiig area of the Warta Nabada district, hospital director Mohamed Abas told Al Jazeera.
Al-Shabab claimed responsibility for the midday attack and confirmed it was aimed at the palace.
"We fired nine mortars at the presidential palace and most of them hit their intended target," Abdulaziz Abu Muscab, the group's military spokesman, told Al Jazeera.
"The attack is part of our ongoing operations in Mogadishu," Muscab said.
The group attempted similar mortar attacks on the palace earlier in February, and also in January.