Portugal is acquiring an additional six Viana do Castelo-class OPVs to complement its four existing units. (Janes/Victor Barreira)

Portugal's Ministry of Defence (MoD) has issued a tender for the acquisition and construction of six additional Viana do Castelo-class Navio de Patrulha Oceanico (NPO) offshore patrol vessels (OPVs) for the Portuguese Navy.

The tender, which includes a review of the engineering project, construction of the ships, and integrated logistics support (ILS), is open to shipyards or consortiums from the European Union and NATO.

Interested competitors have 33 days once the tender is sent for publication in the Official Journal of the European Union to deliver their proposals for the NPO3S programme, which is worth EUR300 million (USD320.5 million).

Three bidders will be then downselected for the negotiations phase, which is expected to culminate with a contract awarded to one of them.

The construction of the first ship must start no more than 12 months after the contract becomes effective.

The Portuguese Navy intends to commission the six OPVs between 2026 and 2030, the service told Janes

A computer-generated image of what Singapore's multirole combat vessel might look like. (Singapore Ministry of Defence)

For much of its existence since it was established in 1967 the Republic of Singapore Navy (RSN) – then known as the Singapore Naval Volunteer Force – was concerned with securing the country's territorial waters against threats such as smugglers and pirates.

However, beginning in the 1970s the service underwent a major introspection of its roles and responsibilities. At that time, the relatively tiny island at the southern tip of the Malay Peninsula was growing rapidly as a major port and transhipment hub and there was an urgent need for the country to ensure that ships calling at and departing from its shores were well protected against conventional and non-conventional maritime threats.

Policymakers of the time decided that to continue thriving as a major port of call for ships plying the east-west maritime routes the country's navy needed to break out of its mould as a coastguard-like service into a maritime power that projects its forces into the country's sea lines of communication (SLOCs) including those that run through the Strait of Malacca and the South China Sea.

Lastunul , one of three Zborul (Tarantul I)-class corvettes, approved to undergo modernisation. (Romanian Navy)

The Romanian parliament has given the approval for the purchase of two new submarines and two second-hand minehunters for the Romanian Navy as well as modernisation of the service's corvettes, local media reported.

According to a report by Romania's national press agency Agerpres on 18 May, the Romanian parliament approved a request from the Ministry of National Defence for the procurement of two Scorpène-class conventionally powered diesel-electric submarines (SSKs) from French shipbuilder Naval Group. The programme is estimated at EUR2 billion (USD2.14 billion) and is expected to take place over a period of eight years.

The submarine procurement is intended to provide the Romanian Navy with improved anti-surface, anti-submarine, and intelligence-gathering capabilities, both in Romanian territorial waters and in international waters further afield.

Romania currently has one ‘Kilo'-class submarine, Delfinul , which has been out of service since 1995.