Vietnamese President To Lam is expected to discuss expanding defence ties with India during a visit to New Delhi this week, including the potential purchase of BrahMos missiles jointly developed with Russia, two sources said.

India, which has been building up domestic defence manufacturing for local use and exports, has already sold the supersonic cruise missiles to the Philippines and signed a contract with Indonesia in March.

A deal with Vietnam could be worth about 60 billion Indian rupees ($629 million), including training and logistical support, said one of the sources.

India considers Vietnam a key part of its strategy to ensure stability in the Indo-Pacific region amid China’s growing influence.

A third source said some defence cooperation announcements could be made during To Lam’s May 5-7 visit, though no signing of a weapons deal was expected.

To Lam arrived on Tuesday in the eastern city of Bodh Gaya, a Buddhist pilgrimage site, on Tuesday.

All the sources declined to be identified as they were not authorised to talk to the media on government negotiations.

The foreign ministries of India and Vietnam, as well as missile maker BrahMos Aerospace, did not immediately respond to requests for comment. BrahMos is a joint venture between Indian and Russian government entities.

Two-way trade between India and Vietnam crossed $16bn in the last fiscal year and both sides have been keen to expand economic ties.