The UK government has suspended study visas for nationals from Afghanistan, Cameroon, Myanmar and Sudan, with Home Secretary Shabana Mahmood citing abuse of the asylum system as the reason for the measure.

Work visas for Afghan nationals have also been halted as part of the policy changes announced by Mahmood. The Home Secretary said the suspensions were necessary due to what the government characterizes as abuse of the visa system by applicants from these countries.

The announcement comes as part of broader changes to the UK's asylum system that Mahmood is expected to detail in an upcoming speech. According to government sources, the Home Secretary will outline measures to reduce support payments for asylum seekers as part of efforts to tighten the system.

Mahmood is expected to frame these policy changes as necessary to restore public trust in the asylum system. The timing coincides with continued arrivals of migrants crossing the English Channel in small boats, an ongoing challenge for UK immigration policy.

The visa suspensions represent an immediate policy change affecting students and workers from the four specified countries, while the broader asylum support changes are part of what appears to be a comprehensive review of the UK's immigration and asylum procedures.