Seibert said on Monday that Merkel had never left any doubt that she was "committed" to the goal of a balanced budget and this would continue to be the goal, Xinhua reported.
"That, too, is sustainability," stressed Seibert, adding that a wide-ranging discussion about individual climate protection proposals was currently ongoing in the German ministries.
Members of the German Social Democrats (SPD) including Karl Lauterbach and Michael Roth had recently called for new debts to be incurred in order to finance Germany's climate protection targets.
"We need a massive state expansion of renewable energies. The black zero is therefore economically and ecologically nonsensical," Lauterbach told the German newspaper Handelsblatt.
The chairman of the German Greens, Robert Habeck, also pleaded for new debts, telling Deutschlandfunk that investing more in climate protection while increasing other expenditures "would not work".
In contrast, German Minister for Finance Olaf Scholz (SPD) said on Monday that the black zero was not "in danger" despite spending on climate protection and the partial abolition of the solidarity surcharge.
"We can perform the tasks we have set ourselves without incurring new debts," the German finance minister said.
The leader of Merkel's conservative CDU Annegret Kramp-Karrenbauer said on German broadcaster n-tv that "we want sustainability".
But there is no reason to start by saying we are giving up sound fiscal policy," stressed Kramp-Karrenbauer.
On Sunday, Kramp-Karrenbauer and Andreas Jung, deputy chairman of the CDU/CSU parliamentary group had called for a "comprehensive tax reform" in the energy sector as a means for more climate protection in Germany.
"We do not have too few taxes, we have too little control. If a CO2 cap were to be put in traffic and buildings, there would also have to be relief for citizens and businesses," Kramp-Karrenbauer and Jung told the German newspaper Welt am Sonntag.
Other members of the German conservative CDU, however, spoke out against tax increases or new debts to finance climate protection.
"I do not understand the Berlin politic at all who think that if there is so much money, they can take more money from somewhere, from tax increases or through debt," said Mike Mohring, leader of the CDU in the federal state of Thuringia.
Saxony's Minister-President Michael Kretschmer (CDU) underlined that "with me, there will be no CO2 tax which would burden German consumers and endanger German jobs," cautioned Kretschmer.
( With inputs from IANS )