Eight Type 26 frigates are due to be built on the Clyde, but the UK government has not announced a timescale for the project.
Harriet Baldwin faced calls from SNP and Labour MPs to confirm a time-frame for cutting steel on the frigates.
But she said it would be "inappropriate" to do so as negotiations continue.
Work had originally been due to start this year, but SNP defence spokesman Brendan O'Hara predicted during a Commons debate on Tuesday that construction of the ships would not start until at least the summer of next year.
He also said the delays could be in part blamed on the economic impact of Brexit, as well as the government committing too much of its procurement budget to renewing the Trident nuclear deterrent.
Mr O'Hara told MPs: "It would be an unforgivable betrayal of the Clyde workers if they were the ones that had to pay the price of Brexit, but also the price of Trident."
In reply, Ms Baldwin told the Westminster Hall debate: "The timing of the award of the build contract and the build schedule itself are key components of the ongoing commercial negotiations between the Government and BAE Systems.
"We are negotiating a deal that aims to optimise the requirements of the Royal Navy in terms of the capability the ships will deliver, to achieve value for money for defence and the taxpayer, and to deliver a build schedule that drives performance.
"These negotiations are continuing, so I am not this afternoon in a position to give a specific date as to when an agreement will be reached.
"To protect the commercial interests of the Ministry of Defence, disclosing any such detail would be inappropriate at this time."
Under questioning from the SNP's Chris Stephens, Ms Baldwin confirmed the national ship building strategy will report by the time of the Autumn Statement on 23 November, which could reveal fresh information about plans for the Type 26 frigates.
Ms Baldwin also resisted calls to disclose further reasons behind delays and cuts to the project.
The project has already been cut from 13 to eight new ships, while a target to start cutting steel in May has been delayed indefinitely.
Tory MP Bob Stewart, a former British Army officer, said: "I don't think we need the minister to answer that - the answer is we had no money.
"That's why we had to cut down the number of Type 26 ships. We did not have the money, and we actually had to cut our means to suit our coat."
SNP MP Martin Docherty-Hughes said the delays left Scotland and the United Kingdom "dangerously under-defended", adding it was a "tale of under-investment and neglect".
A defence minister has refused to say when the next generation of Royal Navy warships will be built.