Germany and Austria said on Thursday they will impose a travel ban on Bosnia's ethnic Serb leader Milorad Dodik and two others accused of undermining the Balkan state's constitution.

Senior figures from Bosnia's Serb entity Republika Srpska (RS) had taken actions to "deliberately weaken the state," the foreign ministries of Austria and Germany said in a joint statement.

Austria's Foreign Minister Beate Meinl-Reisinger and Germany's minister for Europe Anna Luehrmann discussed the situation in Bosnia at a meeting in the capital Sarajevo.

Following the meeting, the ministries said "decisive action" was needed to censure those said to have provoked the constitutional crisis.

"To this end, measures are being initiated that will prevent the three responsible RS politicians from entering Austria and Germany in the future," they said.

Besides Dodik, Prime Minister Radovan Viskovic and the speaker of the RS assembly Nenad Stevandic would be targeted by the travel ban, a spokesman for the Austrian foreign ministry told AFP.

The three are being investigated in Bosnia over alleged moves to bring about the secession of the Serb entity and flouting Bosnia's constitution.

Dodik sought to bar national police and judicial officials from working in the statelet before the order was suspended by Bosnia's constitutional court.

Bosnia issued arrest warrants for Dodik, Viskovic and Stevandic last month, but authorities have deemed it too risky to bring the politicians into custody.

Dodik has travelled to Serbia, Israel and Russia in recent weeks.

The 66-year-old had "taken his secessionist provocations and actions to a new level and has also clearly crossed legal red lines," Meinl-Reisinger said in the statement.

Attacks on Bosnia's constitutional order were threatening the country's "future in the European Union," Luehrmann said.

Together, the German and Austrian ministries called on "all actors involved... to promote calm and stability in order to avoid further escalation".