Europe should respond to the apparent escalation of the conflict in Ukraine by agreeing to further sanctions against Russia at a European Union summit this weekend, two senior German lawmakers close to Chancellor Angela Merkel told Reuters on Thursday.
Ukrainian President Petro Poroshenko said on Thursday that Russian forces had entered his country and the military conflict was worsening after Russian-backed separatists swept into a key town in the east.
Accusations of direct Russian support for the separatist rebels in Ukraine have prompted Western governments to impose sanctions on Moscow, despite its vehement denials.
"It's important that the EU and the West react to this military escalation by Putin," said Norbert Roettgen, chairman of parliament's foreign policy committee and senior member of parliament for Merkel's Christian Democrats (CDU).
Roettgen said in an interview with Reuters that it was clear Russia now had a military presence in Ukraine, "with tanks and soldiers".
"There must be new sanctions as an answer and that needs to be discussed at the summit and, ideally, agreed to right away," he said.
"Any hesitation would be seen by (Russian President Vladimir) Putin as European weakness that would encourage him to keep going," said the conservative politician.
Germany, with close trade and energy ties with Russia, long resisted tougher sanctions before agreeing to stronger measures after a Malaysian airliner was shot down over rebel-held territory in July.
Another senior CDU lawmaker, deputy parliamentary floor leader Andreas Schockenhoff, also told Reuters that further sanctions against Russia were needed.
"The conflict has become an undeclared war," Schockenhoff said. "If the reports about the activities of the Russian military in Ukraine are confirmed, then there must be tougher sanctions against Russia."