Myanmar has asked Beijing for co-operation to help prevent "terrorists" from using Chinese territory to launch cross-border attacks.
Martial law has been declared in north-east Myanmar after heavy fighting between the military and ethnic-minority rebels.
Army chiefs have accused "foreign powers" of supporting the insurgents.
The Chinese government denies backing the rebels and has called for a peaceful resolution to the fighting.
On Thursday, Hmuu Zaw, an official from the office of Myanmar President Thein Sein, published a statement on Facebook which alluded to cross-border attacks.
He said: "It is necessary to co-operate…on the understanding that terrorist attacks on Myanmar are not allowed from Chinese territory."
Chinese officials were not available to comment on the statement, reported the Reuters news agency.
Sporadic clashes continued in the north-eastern Kokang region on Thursday, though they were not as intense as in recent days.
Since 9 February the military has been battling the National Democratic Alliance Army (MNDAA), a group aiming to achieve autonomy for Kokang.
At least 50 government soldiers and 26 rebels have been killed in the fighting.
Tens of thousands of refugees have also been forced to flee their homes.
