Mr Sommat said divers were trying to retrieve the black box from the river, after it was located by the search team.
He thanked Thai police and military personnel for their help in the search and recovery operation.
Pol Maj Gen Wallop Raksanoh, chief of the Thai military search team, said the Thai soldiers would stop work on Monday. Lao authorities said they are capable of concluding the search for bodies and the aircraft's fuselage. The Thai team would leave Pakse on Tuesday and return home, he added.
Pol Gen Charumporn Suramanee, an adviser to the Royal Thai Police Office and chief of Thailand's Disaster Victims Identification (DIV) team, said 42 bodies and 17 body parts had been recovered.
Sixteen of the bodies found have been identified. They included those of two Thai victims - Phakkawat Atiratanachai and Kanueng Chartkasemchai.
He said 37 samples of human remains were sent to Bangkok on Sunday night for DNA tests, adding that he thought the other bodies would soon be identified.
On Monday afternoon, the bodies of six victims were recovered but not yet identified. They were to be examined and compared with fingerprint and dental records and descriptions provided by relatives for identification.
A report said one of the bodies yet to be identified might be that of Thai victim, Veekij Busarawuthanu.
Rattanamanee Khounewong, Deputy Minister of Public Works and Transport, said Lao Airlines would initially pay US$5,000 to the relatives of each of the Thai victims and provide air transport to deliver their bodies to their hometowns in Thailand.
Relatives of three of the Thai victims - Phakkawat, Kanueng and Veekij - said they had demanded $500,000 compensation each from Lao Airlines.
The bodies of two other Thai victims and PTT employees - Yanyong Apa-anant and Niphon Chaichanasakuldee - have not been recovered.
Lao government offices on Monday observed a minute of silence to pay tribute to the people who died in the airplane crash.
A separate ceremony was held at the same time near the site of the crash in Pakse, to commemorate the dead, more than half of whom were foreign nationals.
Lao Airlines Flight QV 301 from the capital Vientiane to the southern city of Pakse crashed Wednesday after hitting turbulence. The national airline is a state-owned enterprise.
Search teams have been slowed by strong currents and turbid waters in the Mekong.
"We can identify the general location of the plane, but have not yet been able to find it," Yakua Lopangkao, director general of the department of civil aviation, told the Vientiane Times.
The twin-engine turboprop ATR 72-600 had been delivered from the French-Italian aircraft maker in March.
Experts from ATR arrived in Laos over the weekend to assist with investigations into the crash.
There were 44 passengers aboard comprising 16 Lao, seven French nationals, six Australians, five Thais, three South Koreans, three Vietnamese, one American, one Chinese, one Canadian, one Malaysian national, and one person from Taiwan. There were also five crew. All on board were killed.