Russian President Vladimir Putin has not ruled out running for president again beyond 2024, when his term ends.
But he told parliament that the Constitutional Court would first have to approve such a step. An MP has proposed "resetting to zero" the number of presidential terms.
Mr Putin however rejected as "not expedient" a proposal to scrap the current rule that a president can serve no more than two consecutive terms.
He has been in power for 20 years.
But for part of that time he served as prime minister, meaning he did not have more than two consecutive presidential terms. The majority of MPs in parliament - the State Duma - are Putin supporters.
Russia will hold a "public vote" on 22 April to decide if constitutional changes will go ahead. They could significantly alter the balance of power between the presidency and parliament.
The amendments addressed by Mr Putin in his televised speech on Tuesday were put forward by MP Valentina Tereshkova, the first woman in space and a strong supporter of his presidency.
The "reset to zero" proposal would, according to Mr Putin, mean "removing the restriction for any person, any citizen, including the current president, and allowing them to take part in elections in the future, naturally in open and competitive elections".
It could go ahead if approved by citizens in the public vote on 22 April, he said, and "if the Constitutional Court rules such an amendment would not go against (the constitution)".
That amendment has now been approved by the Duma.
Mr Putin also said he saw no need for early elections to the Duma, rejecting another MP's proposal.
He triggered intense debate about changing the constitution when, unexpectedly, he put forward draft amendments in January. He proposed transferring some powers from the presidency to parliament.
In his speech on Tuesday, he said "a strong presidency is absolutely essential", but he added that the Duma "should get wider powers".
Such changes were needed, he said, "to strengthen our sovereignty, traditions and values" in a world in the throes of fundamental change, including new challenges such as digital technology and coronavirus.
In the long term, he said, Russia "needs a guarantee that the people in power can be changed regularly", and he insisted that "elections must be open and competitive".
He also ruled out a Western-style parliamentary system, remarking that "for years in some European countries they cannot form a government".
