The Russian Foreign Ministry has rejected what it says are unacceptable demands by Germany and France to release Ukrainian soldiers held by Russia.
The statement by the Russian Foreign Ministry on December 29 follows an appeal by German Chancellor Angela Merkel and French President Emmanuel Macron in a statement on December 28.
Russia is holding the 24 Ukrainian sailors after capturing them along with their Ukrainian naval vessels last month near the Kerch Strait, which links the Black Sea and Sea of Azov.
Moscow alleged that the vessels had illegally entered Russian territorial waters near Crimea, which Russia occupied and annexed from Ukraine in 2014.
Ukraine and most UN member states do not recognize the annexation.
Macron and Merkel said in their joint statement on December 28 that these "excessive inspections" were a source of "deep concern."
"We call for all ships using the Kerch Strait to be given safe, free, and unhindered passage, and for the immediate and unconditional release of the Ukrainian sailors. They too must be allowed to spend the holidays with their families."
Kremlin spokesman Dmitry Peskov said Russian President Vladimir Putin had discussed demands to free the sailors with Merkel. However, Peskov said Russia would "act in accordance with Russian law," Russian news agencies quoted him as saying on December 29.
The European Union and the United States say Russia's actions were illegal and have called on Moscow to immediately return the vessels and their crews to Ukraine.
Merkel and Macron also welcomed a cease-fire that took effect at 12:01 a.m. on December 29 in the conflict area of eastern Ukraine.
"The approach of the New Year's and Orthodox Christmas holidays must serve as an opportunity for the stakeholders in the conflict in eastern Ukraine to focus on the needs of civilians, who have suffered all too long as a result of this conflict and its consequences," the leaders said.
"The guarantee of a safe and secure environment should enable the implementation of crucial humanitarian measures. We now call on the parties to assume their full responsibilities, especially with regard to civilians in the area."
The Special Monitoring Mission of the Organization for Security and Cooperation in Europe (OSCE) also welcomed the deal to establish the New Year's cease-fire in eastern Ukraine.
On December 26, Ukrainian President Petro Poroshenko announced the end of martial law in the country's borders regions that was imposed following Russia's seizure of the sailors and their ships in the Black Sea.
Ukrainian government forces have been fighting against Russia-backed separatists in eastern Ukraine since April 2014, shortly after Russia seized Ukraine's Crimean Peninsula and forcibly annexed it. Some 10,300 people have been killed in the fighting since early 2014.
Although Moscow denies interfering in Ukraine's domestic affairs, the International Criminal Court in November 2016 ruled that the fighting in eastern Ukraine was "an international armed conflict between Ukraine and the Russian Federation."
The current truce is scheduled to run through at least January 7 and was reached by the Trilateral Contact Group on Ukraine, which consists of Ukraine, Russia, and the OSCE.
Several cease-fires have been called in the region as part of the so-called Minsk agreements, but none has met with success.