As shown in the attached picture, I wish to draw that red arc between the left node and the right node and label it as ABC (shown in attached image).
How can I do it? The code that I have worked out till now is given as follows:
\begin{tikzpicture}
\begin{scope}[minimum width=15mm,minimum height=10mm]
\node[draw,line width=0.25mm,rounded corners, label=
{[align=center]above:ABCD\\ abcdefgh 123 \\mnopqr}] (v1) at (0,0) {$G_F(s)$};
\node[draw,line width=0.25mm,rounded corners, label=
{[align=center]above:mnomno \\ xyzxyzxyz}] (v2) at ($(v1)+(10,0)$) {$R(s)$};
\node[draw,line width=0.25mm,rounded corners, label={[align=center]below: \\ abcdef integer\\abcedef}] (v3) at ($(v1)+(5,-4)$) {$G_{I}(s)$};
\end{scope}
\draw[->] (v1) -- (v2) node[pos=0.5,sloped,above]{ABCDEF
approach}node[pos=0.5,sloped,below]{\textcolor{red}{\textbf{Proposed
approach}}};
\draw[->] (v1) -- (v3) node[pos=0.5,sloped,above]{Approach 1}; ;
\draw[->] (v3) -- (v2)node[pos=0.5,sloped,above]{Approach 2};
\end{tikzpicture}