Execute command usage fails

Question

*** Settings ***

    Documentation      Transfer a file from OCU to PC
    Library            SSHLibrary
    Suite Setup        Open Connection and Login With Public Key
    Suite Teardown     Close All Connections

*** Variables ***

    ${REMOTE HOST}    192.168.x.xxx
    ${USER}           xxx

*** Keywords ***

    Open Connection and Login With Public Key

    Open Connection     ${REMOTE HOST} 
    Login With Public Key     ${USER}     /home/bhushan/.ssh/id_rsa

*** Test Cases ***


    Run the given command on the console

    ${pwd}= Execute Command     pwd

    Should Be Equal     ${pwd}      /home/root 

    ${output}=  Execute Command     ls

    ${output}=  Execute Command        scp /home/root/myfile.txt [email protected]:/home/bhushan/vdr-reports/
    Log ${output} 

I have Dropbear of the latest version installed on my target. I am trying to run the above SSH Library Robot framework keyword based test case which defines to transfer a file from remote to the local host. The execute command keyword works in the beginning i.e. ${output}= Execute Command ls, but i am getting an error while using the same keyword in copying the files, i.e i can't see anything happening on the console. It is hanging and i waited for long time to see the output but haven't seen anything. But this works when i copy the files to my local machine manually. Can anyone here try to help me in fixing this error.

KEYWORD ${output} = SSHLibrary . Execute Command scp /home/root/myfile.txt [email protected]:/home/bhushan/vdr-reports/ Documentation: Executes command on the remote machine and returns its outputs. Start / End / Elapsed: 20170829 10:26:23.897 / 20170829 10:26:50.148 / 00:00:26.251 10:26:23.898 INFO Executing command 'scp /home/root/myfile.txt [email protected]:/home/bhushan/vdr-reports/'...................>

This is what i see in the log